OBJECTIVE: To present the prescribing patterns of general practitioners (GPs) at public primary care centres (PPCCs) in Halland, a county in the south-west of Sweden. GP share of the total prescribing of different drug groups 1988-1997 is presented, as well as changes in patterns. DESIGN: A descriptive prescription study performed 3 months each year in 10 consecutive years. SETTING: Medical service and pharmacies in Halland. SUBJECTS: Prescriptions from about 100 GPs of PPCCs and 550 physicians of various other specialties. MAIN OUTCOME MEASURES: Percentages and absolute numbers of GPs prescribing. RESULTS: GPs prescribed 45% and 51% of the prescriptions from physicians in 1988 and 1997, respectively, while the cost shares were 40% and 42%. An increase in prescriptions was seen both in relative and in absolute numbers (from 117414 in 3 months in 1988 to 161012 in 1995). The increase in cost per DDD (defined daily dose) during the study period was 47% for GPs and 72% for other doctors. CONCLUSIONS: GP prescribing increased in both absolute and relative numbers, while the cost increase per DDD was moderate compared to other physicians.