Using data drawn from 2010, 2012, and 2013 American Time Use Survey Well-Being Modules, this paper examines the existence of son preference among fathers in the U.S. by estimating the effect of child gender on the fathers' subjective well-being. A wide range of subjective well-being measures, including happiness, pain, sadness, stress, tiredness, and meaningfulness, is analyzed, and fixed-effects models are adopted to control for unobserved individual heterogeneity. The results from the full sample show that fathers feel less sad and tired when interacting with both sons and daughters versus with daughters only. In families with only one child, fathers report no difference in subjective well-being when spending time with a son versus with a daughter. By further stratifying this sample of fathers by child's age of three, we continue to find no difference in paternal subjective well-being between being with a son and with a daughter when the child is younger than three. However, when the child is three or older, we find that fathers feel less stressed and more meaningful being with a son versus with a daughter. The results from Asian fathers in the U.S., in contrast, show a tremendous reduction in stress in activities with sons only than with daughters only. These results indicate no evidence of son preference in the general U.S. population. If there is any, it only exists among Asian fathers in the U.S.