Background: A cultural preference for sons has been well documented in India, resulting in skewed sex ratios, especially exhibited in northwest India. Previous research has shown that family sex composition is associated with family planning (FP) use and couples’ desire for more children. This study examines family sex composition and fertility and FP behaviors in urban Uttar Pradesh, India; little work has examined these issues in urban settings where family sizes are smaller and FP use is common. Methods: Data for this analysis comes from a 2010 representative survey of married, non-pregnant fecund women aged 15–49 from six cities in Uttar Pradesh, India. Multivariate analyses are used to examine the association between family sex composition and fertility desires and FP use. Results: The multivariate results indicate that family sex composition is associated with fertility desires and FP use. Women without living children and without at least one child of each sex are significantly less likely to want no more children and women with both sons and daughters but more sons are significantly more likely to want no more children as compared to women that have both sons and daughters but more daughters. Women with no living children and women with daughters but no sons are less likely to be modern FP users than nonusers whereas women with both sons and daughters but more sons are more likely to be modern FP users than nonusers as compared to women with both sons and daughters but more daughters. Conclusions: These findings confirm that family sex composition affects fertility behavior and also reveals that preference for sons persists in urban Uttar Pradesh. These results underscore the importance of programs and policies that work to enhance the value of girl children.