To introduce a new cat to your cat, begin with separate spaces and progress from scent swapping to protected barrier sightings before attempting short, voluntary, supervised meetings. Watch both cats closely, keep independent escape routes open at all times, and return to an earlier stage whenever either cat shows tension. Use their responses, not a calendar deadline.
This guide covers introducing an unfamiliar adult cat to a resident adult cat. The practical goal is a low-stress, step-by-step introduction that preserves choice and safe territory for both individuals.
Prepare two places the cats can keep using
Blue Cross’s cat-introduction guide recommends setting up a dedicated settling room for the new arrival—ideally an area your resident cat rarely uses. Equip that room with the new cat’s own bed, food bowl, water bowl, scratching post, hiding spot, and litter tray so both cats keep secure, separate retreats throughout the process.
Protect the resident cat’s routine and core territory at the same time. Keep feeding, water, resting, and toileting stations separate rather than placing bowls near a shared door to force proximity, and never carry or push either cat toward the other.
Use our home care plan to organize daily household duties across caregivers, and see our guide to independent litter-box locations for why separate tray locations matter in a multi-cat home.
Offer scent with the choice to ignore it
Cats Protection’s staged introduction guide describes gently wiping a soft cloth around one cat’s cheeks and forehead to collect facial pheromones, then placing the cloth on the floor in the other cat’s space so they can sniff or walk past it freely. Never hold a scent cloth against a cat’s nose or force investigation. Move forward to visual contact only when both cats remain relaxed around each other’s scent.
Let a barrier provide sight without direct contact
Blue Cross recommends brief initial sightings through a physical barrier—such as a tall pet gate, screen door, or securely cracked door gap—that prevents physical contact. Keep generous distance on both sides and leave each cat’s retreat open so either can watch from afar or walk away. If either cat hisses, growls, crouches, or hides, step back to complete separation and scent swapping rather than opening the barrier.
Always evaluate both participants before repeating or advancing a step. Noting that “the new cat walked up to the gate” describes only half of the encounter; you also need to record what the resident cat did and whether both cats stayed relaxed.
Keep supervised meetings brief and optional
Battersea’s adult-cat introduction guidance progresses from calm barrier sightings to short, supervised face-to-face sessions with high-value treats or play available and the settling room door left open as a retreat. Never restrain either cat in a carrier or on a lead during a meeting—calmly ignoring one another in the same room is a positive outcome, and you do not need to encourage nose-to-nose contact.
Use both cats' responses to choose the next step
| What You Notice in Either Adult Cat (Battersea Stage Context) | Next Step in Battersea’s Sequence |
|---|---|
| Fixed staring, growling, hissing, or hiding during barrier visual contact | Close visual access and return to separate rooms with scent familiarization. |
| Both cats calmly ignore each other or explore at a distance during a supervised room session | Keep interaction completely optional and end the short session while both remain relaxed. |
| Persistent growling, stalking, blocking, or swatting during supervised meetings | End the session calmly without punishment and step back to an earlier barrier or scent stage. |
If tension persists despite returning to earlier stages, consult your veterinary team to rule out pain or illness and work with a qualified feline behavior professional.
Use the copyable two-cat observation log below after each session so you record both the resident cat and the new adult cat side by side. Writing down specific observations—such as “watched from the doorway, then walked away”—prevents treating one bold cat’s approach as mutual readiness. Completing a log row is simply a way to track your next stage decision, not a compatibility test or a deadline schedule:
| Introduction Stage | Resident Adult Cat’s Response & Retreat Used | New Adult Cat’s Response & Retreat Used | Available Escape Route Checked | Next Step (Stay, Advance, or Step Back) |
|---|---|---|---|---|
| Stage 2: Scent cloth swap (Illustrative example) | Sniffed cloth briefly, rubbed cheek on nearby chair, ate meal normally | Sniffed cloth from 1 ft away, then curled up in settling-room bed | Both cats in separate closed rooms with full resource stations | Stay / Repeat: Offer scent cloth again tomorrow before trying barrier sight |
| Stage 3: Barrier sighting (Illustrative divergence example) | Backed away from gate and hid under sofa when new cat approached | Approached gate curiously with ears forward | Hallway and living-room retreats open on resident side; settling room open on new-cat side | Step Back: Do not advance pair; return to separate rooms and scent work |
| Stage 4: Short supervised room visit (Illustrative calm example) | “Watched from the doorway, then walked away” to window perch | Explored rug near settling-room door, ignored resident cat, returned to own room | Settling-room door propped open; high perches and hallway exit unobstructed | Stay at Stage 4: Keep next supervised visit equally short and optional |
As Cats Protection notes, there is no fixed number of days for adult cats to adjust, and some cats prefer peaceful avoidance over close companionship.
