Due to the technical difficulties involved in identifying BRCA1/2 genetic mutations, the affected patients have to be investigated before testing can be made available to all the relatives at risk. Here, we studied the attendance rates at cancer genetic clinics (CGC) and the uptake of genetic testing in first/second degree relatives after the first BRCA1 mutated woman with cancer had been informed in the family. We carried out a survey on French cancer geneticists involved in breast/ovarian CGC, asking them to select their first three BRCA1 family records. Data collection was carried out retrospectively by telephone interview with a standardised closed item questionnaire. Considering only those families (n = 37) where the index case had been informed for at least 8 months at the time of the survey, the overall attendance at CGC of first/second degree relatives (n = 419) was 31.7% (n = 133) and the overall uptake of BRCA1 testing was 26.7% (n = 112). Among those who attended the CGC (n = 133), 84.2% (n = 112) requested genetic testing (95% confidence interval: 78-90.4%). Among the first degree relatives, the unaffected women who attended accounted for 59.8% and 51.2% requested testing after the index case had been informed. Women with cancer had a higher attendance rate (83.3%) than unaffected women (36.1%) (Odds Ratio (OR) = 8.86; p < 0.001) and first degree relatives (51.4%) than second degree relatives (17.9%) (OR = 2.87; p < 0.001); women (43%) also attended more frequently than men (16%) (OR = 3.97, p < 0.001). In French BRCA1 mutated families, female first degree relatives of the index patient show the most interest in genetic testing.