This paper examines the values, variance and some possible determinants of sex ratios for the first child and for all children in expected and desired families. For adults in Tallahassee, Florida, it was found that a large majority of respondents within sixty demographic categories chose males for their first child. Of those who actually had girls for their first child, a plurality would, nevertheless, prefer a first boy in their desired family. It was hypothesized and demonstrated that sex-role ideologies were a strong predictor of variance in first-child sex preferences. Sex ratios for all children in expected and desired families were 116 and 113, respectively. If people could choose the sex of their future children, these data suggest that several population parameters might be significantly altered; a preliminary model is outlined which might project some of these changes.