The side-effects encountered by 1,090 patients taking the oral contraceptive pill were reviewed. The main side-effects were migraine, headaches, weight gain, depression, and irregular bleeding. Reasons for changing the Pill are discussed, and recommendations are suggested for a way of monitoring patients taking the Pill. Analysis of the results show that 50 per cent of patients are happy with their first Pill, and that the 30 microgram pill produces fewer side-effects.