Duration: April 1993 - June 2012 In 1993, Sigma Research carried out an on-the-spot survey of men attending the London Lesbian and Gay Pride festival, instigating an annual survey that has grown to be the largest in the world and an institution on the UK summer gay scene. The National Gay Men’s Sex Survey (GMSS), also known as Vital Statistics, now recruits men via booklets and online. To find out more about the history of GMSS, the methods used, collaborators, questionnaires and all the outputs associated with it go to our specific GMSS website. The content of the survey is developed in collaboration with health promoters, within the framework of Making it Count. The questions cover a range of demographics, health indicators, sexual behaviours, HIV prevention needs, use of settings in which health promotion can occur and recognition of national interventions. The weight given to each area varies each year, and the data collected is treated as cumulative, building a detailed picture of gay men and bisexual men and HIV over time. Core results from the national sample are reported in the main annual survey report, published in the year following each survey. We also publish and insert into various gay press titles feedback to respondents who may have taken part. Since 2003 detailed data reports have also been made available alongside the national reports.These reports group men by their region of residence for each country, and for English residents by their Primary Care Trust of residence within each Strategic Health Authority. Data about the performance of national interventions appears in specific CHAPS Evaluation Reports. Findings from the survey have also been presented at a range of national and international conferences and in Journal articles.