Previous results show that gender diversity increases the probability firms' innovation. This paper explores the relationship between gender diversity of R&D departments and their capacity to patent. Based on the Spanish Community Innovation Survey between 2004 and 2014, we have applied a two-step procedure control for endogeneity. Our results show that gender diversity affects a firm's capacity to patent in different manners depending on the coverage of the patents. On the one hand, gender diversity affects OEPM patents negatively, while the impact becomes positive for patents with an international coverage (EPO, USPTO, or PCT). This analysis is relevant in order reveal the dual effect of gender diversity within R&D teams on their capacity to process and register patents.