FEMALE choice of mates based on the expression of characters that correlate with male quality remains a controversial and largely untested idea1. By choosing quality males, females stand to gain resources2, genetic benefits for their offspring3-5, or both. In the house finch (Carpodacus mexicanus), male plumage coloration is a function of dietary intake of carotenoids6,7. Here I present results of field studies that indicate that females prefer to mate with colourful males and that plumage brightness correlates with a male's capactity for parental care and perhaps its genotypic quality. Artificially brightened males paired more quickly and frequently than sham control or lightened males. Among unmanipulated males, plumage coloration was correlated with nest attentiveness and overwinter survival. In addition, there was a positive correlation between the coloration of fathers and sons.