Fathers' vocabulary to infants has been linked in the literature to early child language development, however, little is known about the variability in fathers' language behavior. This study considered associations between fathers' work characteristics and fathers' vocabulary among a sample of employed African American fathers of 6-month-old infants who were living in low-income rural communities. After controlling for family and individual factors, we found that fathers who worked nonstandard shifts and reported more job flexibility used more diverse vocabulary with their infants. (Contains 3 tables.)