Abstract Objective To assess the reasons for over-the-counter (OTC) medicine use in children and the sociodemographic factors influencing this choice of self-care rather than GP consultation. Method Questionnaires were sent to the home address of a randomly generated list of children under 12 years of age from three GP practices in the East Midlands selected to represent bottom, middle and top tertiles of deprivation on the basis of the Jarman score. Analysis using chi-square and Mann-Whitney tests was used to identify associated factors (number of carers in the home, number of children, deprivation score, parent/carer's age, age and number of children in the house) of the responses. Setting Primary care setting in the East Midlands region of England. Key findings From 424 completed questionnaires returned (response rate 61%), 413 parents/carers had purchased OTC medicines. Fifty-one different products had been purchased, with analgesic/antipyretic and cough/cold remedies the most frequently bought. The most commonly reported reasons for parent/carer initiated medication were to avoid troubling the GP with minor childhood ailments (79% of respondents) and to have medicines available in case of future need (74%). Cost was a barrier to buying OTC medicines for the more deprived. Advice-seeking behaviour was associated with the symptom, the number of children, affluence and the age of the child. Conclusion Parent/carer initiated use of OTC medication is widespread, particularly for analgesic/antipyretic and cough/cold remedies. Differences in advice-seeking behaviour are associated with the presenting symptom and a variety of sociodemographic factors.