Stray dogs and cats are a common sight on the Greek§Islands. §Overpopulation increases spread of infectious§diseases and §transmission of zoonotic agents. Population control§must be performed on different levels including legislation, §registration/identification, garbage control, habitat§control, §neutering of pets and stray dogs and cats, control of§breeders/sales, §and education of the public. Evaluative studies are§essential for the §selection of a protocol and may lead to a different§approach for each §species. The purpose of the study reported here was§to evaluate the §roots of the stray cat and dog problem and to monitor§the success §of a catch-neuter-release program on one Greek§island. This report §should offer a practical guideline to Non Government§Organizations §(NGO s) and municipalities for a successful§population control §program.