This study aims to: 1) assess the proportion of General Practioners (GPs) who are aware of or who have read the National Institute for Health and Clinical Excellence (NICE; 2005a) guidelines for Obsessive Compulsive Disorder (OCD), 2) compare this with the proportion of other mental health disorders found by previous research and 3) establish the prevalence of OCD in primary care. Questionnaires were sent to all GPs (n = 795) and practice managers (n = 157) in Berkshire and Buckinghamshire, South East England. These contained 19 questions and took 5 min to complete. After the first set of responses, larger practices were visited and telephoned to encourage further responses. The response rates were 10.1% from GPs and 19.1% from practice managers. In all, 48.7% of the GPs were aware of the NICE guidelines for OCD and 30.3% reported that they had read them – higher than for Post-Traumatic Stress Disorder, but lower than for depression. Of registered patients, 0.2% were diagnosed with OCD, lower than the 1.1% found in epidemiological studies.