The phenotype linked fertility hypothesis proposes that sexual selection should favour females who can accurately assess the fertilization potential of available mates and preferentially avoid mating with males who may be sperm depleted so as to minimize the risks associated with reproduction. I investigated experimentally whether females of the Trinidadian guppy are able to assess male functional fertility using a wide range of sensory cues and choose to avoid mating with males who may be sperm limited. On average, females avoided males that were apparently previously mated or actually sperm depleted, while exhibiting a strong preference for the other non sperm depleted male. Both visual and chemical cues from males appear to reveal their potential functional fertility and such cues were used by females to discriminate between sperm depleted and non sperm depleted males. My novel results are important as they support the above stated hypithesis.