The Weekly Returns Service (WRS) of the Royal College of General Practitioners (RCGP) is a sentinel network of general practitioners (GPs) reporting patient morbidity and encounter data. In 2009, 101 practices contributed to the WRS, with 75 of these delivering data for 50 weeks or more. This annual report includes data on disease incidence gleaned from patient visits. The report describes the representativeness of the WRS, and gives the underlying population numbers by regions, sex, and age groups. Extensive appendices summarize annual incidence rates by sex and age group, at the ICD-9 chapter level, and for a select group of more specific causes. For each group of causes, data are also given on number of episodes and consultations.