The influence that the level of training and practice setting have on the patterns of primary care provided by nurses at the Frontier Nursing Service (FNS) is assessed. The Frontier Nursing Service is the only available source the residents of Leslie County, Kentucky have for primary care; it utilizes nurses for the management of approximately 80% of its primary care patients. Patterns of care given by family nurse practitioners and registered nurses at FNS during 1974 were analyzed according to two tracer conditions, otitis media and urinary tract infection. Data were obtained from the encounter forms that are filled out for all primary care visits to FNS. Computerized routines were developed to group the relevant encounters into episodes of care for the two tracer conditions. Results indicate that the practice setting, rather than the level of training, has the strongest effect on the patterns of primary care rendered by nurses in a rural environment such as FNS.