Bone morphogenetic proteins are members of the transforming growth factor‐β superfamily that have multiple functions in the developing nervous system. One of them, bone morphogenetic protein‐2 (BMP‐2), promotes the differentiation of cultured striatal neurones, enhancing dendrite growth and calbindin‐positive phenotype. Bone morphogenetic proteins have been implicated in cooperative interactions with other neurotrophic factors. Here we examined whether the effects of BMP‐2 on cultured striatal neurones are mediated or enhanced by other neurotrophic factors. BMP‐2 had a cooperative effect with low doses of brain‐derived neurotrophic factor or neurotrophin‐3 (but not with other neurotrophic factors such as glial cell line‐derived neurotrophic factor, neurturin or transforming growth factor‐β2) on the number of calbindin‐positive striatal neurones. Moreover, BMP‐2 induced phosphorylated Trk immunoreactivity in cultured striatal neurones, suggesting that neurotrophins are involved in BMP‐2 neurotrophic effects. The addition of TrkB‐IgG or antibodies against brain‐derived neurotrophic factor abolished the effects of BMP‐2 on the number and degree of differentiation of calbindin‐positive striatal neurones. Indeed, BMP‐2 treatment increased brain‐derived neurotrophic factor protein levels in treated cultures media and BDNF immunocytochemistry revealed that this neurotrophin was produced by neuronal cells. Taken together, these results indicate that brain‐derived neurotrophic factor mediates the effects of BMP‐2 on striatal neurones.