This article carries on a discussion on reproduction and gender based on interviews
with men in a human reproduction clinic in the city of Campinas (SP, Brazil),who were seeking
treatment for sterility or information about methods of family planning. The object of the research
was to investigate male representations of paternity, analyzing what this revealed about
masculinity and the ways in which gender is constituted. The study found associations between
paternity and masculinity, between fertility and masculinity, but always mediated by gender
and by specific connections. The study led to a reflection on conception theories, especially on
how a duogenetic theory of reproduction is present in the representations of the people
interviewed about paternity and maternity