ObjectivesThe acceleration in the number of female doctors has led to questions about differences in how men and women practice medicine. The aim of this study was to assess the influence of general practitioner (GP) gender on the use of the three main categories of diagnostic procedures—clinical examinations, laboratory tests and imaging investigations.DesignCross-sectional nationwide multicentre study.SettingFrench training general practices.ParticipantsThe patient sample included all the voluntary patients over a cumulative period of 5 days per office between November 2011 and April 2012. The GP sample included 85 males and 43 females.Methods54 interns in general practice, observing their GP supervisors, collected data about the characteristics of GPs and consultations, as well as the health problems managed during the visit and the processes of care associated with them. Using hierarchical multilevel mixed-effect logistic regression models, we performed multivariable analyses to assess differences in each of the three main categories of diagnostic procedures, and two specific multivariable analyses for each category, distinguishing screening from diagnostic or follow-up procedures. We searched for interactions between GP gender and patient gender or type of health problem managed.ResultsThis analysis of 45 582 health problems managed in 20 613 consultations showed that female GPs performed more clinical examinations than male GPs, both for screening (OR 1.75; 95% CI 1.19 to 2.58) and for diagnostic or follow-up purposes (OR 1.41; 95% CI 1.08 to 1.84). Female GPs also ordered laboratory tests for diagnostic or follow-up purposes more frequently (OR 1.21; 95% CI 1.03 to 1.43). Female GPs performed even more clinical examinations than male GPs to diagnose or follow-up injuries (OR 1.69; 95% CI 1.19 to 2.40).ConclusionFurther research on the appropriateness of diagnostic procedures is required to determine to what extent these differences are related to underuse or overuse.