The Alaotran gentle lemur is one of the most endangered primates in the world and shows a low success rate in captive breeding programmes. We tested a novel scent enrichment, made up of a synthesized mixture potentially conveying information about female fertility, on four unsuccessful breeding pairs (n = 8) hosted at Jersey, Birmingham, London (UK) and Mulhouse (France) zoos. We evaluated the effects of the scent enrichment combining behavioural observations (n = 515 hours) with faecal endocrinology (cortisol and testosterone measurements) (n = 180 samples). We did not find any significant change in affiliative behaviours, while aggressive and abnormal behaviours were rarely observed. However, we found a significant increase of both male and female olfactory behaviours during the enrichment condition, with females performing these behaviours significantly less than males. We also found that sexual behaviours significantly increased over the enrichment period. Conversely, we did not find any significant change related to enrichment in cortisol and testosterone levels. Our findings show little effectiveness by our scent enrichment, which is likely due to shortfalls with regards to fertile odour sampling. However, our results also highlight that biologically relevant odour signals may trigger natural species-specific behaviours, with potential implications for management and conservation breeding of zoo-based endangered species.