GUIDELINES RATIONALE: A cat's level of comfort with its environment is intrinsically linked to its physical health, emotional wellbeing and behavior. Having a basic understanding of the cat's species-specific environmental needs and how cats interact with their environment will provide a foundation for addressing these fundamental requirements. ENVIRONMENTAL NEEDS: Addressing environmental needs is essential (not optional) for optimum wellbeing of the cat. Environmental needs include those relating not only to the cat's physical surroundings (indoors or outdoors; in the home environment or at the veterinary practice) but also those affecting social interaction, including responses to human contact. FIVE 'PILLARS' FRAMEWORK: The authorship panel has organized the Guidelines around five primary concepts ('pillars') that provide the framework for a healthy feline environment. Understanding these principles and the unique environmental needs of the cat will help veterinarians, cat owners and care-givers to reduce stress, the incidence of stress-related disorders, and unwanted behavior in their feline patients and pets. The recommendations in the Guidelines apply to all pet cats, regardless of lifestyle.