Contemporary norms of fatherhood emphasize the dual demands of breadwinning and daily involvement in child care. Recent qualitative research suggests that working-class fathers find it difficult to meet these demands due to job instability and workplace inflexibility. Yet little quantitative research has examined how employment characteristics are related to fathers’ parenting stress, in comparison with mothers’. Analyses using data from the Fragile Families and Child Wellbeing Study (N = 3,165) show that unemployment and workplace inflexibility, but not overwork, multiple jobs, odd jobs, and nonstandard hours, are related to more parenting stress for fathers. Although these two factors are also related to more parenting stress for mothers, nuanced gender differences emerged: these are better predictors than other parental or child characteristics for fathers only, and the effect size of workplace inflexibility is greater for fathers than mothers. In sum, securing a job with flexible schedule is central to reducing fathers’ parenting stress.