Previous results show that gender diversity increases the probability that firms invest in R&D and engage in 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 apply a two-step procedure in order to control for endogeneity. Although gender diversity affects OEPM patents negatively, its impact is non-significant for patents with international coverage (EPO, USPTO, or PCT). A relevant result is the fact that the generation of patents is positively affected by the diversity of categories in the R&D labs. Our results highlight that, gender diversity of R&D teams does not play a relevant impact on the capacity of the firm to register patents. However, the diversity according to the professional role in R&D teams exerts a positive influence. In sum, the key question is not the gender diversity per se but the gender diversity jointly with the professional status.