Father characteristics and psychosocial functioning were examined as predictors of father involvement both with an Early Head Start (EHS) program and with their infant. Variables examined as potential predictors were selected based on the program's emphasis on building relationships as their primary intervention strategy. The 72 low-income fathers included in this study were predominantly Caucasian and married or living with their child's mother. Fathers' characteristics predicted their involvement in expected ways. Fathers were rated as more involved, both with their infants and with the EHS program, when they were better educated, less depressed, more likely to use social support especially spiritual support, and more active in their religion. Fathers who had better relationships with home visitors were those who had these same characteristics and also were less anxious about close relationships. In addition, fathers who were later rated as more engaged with their infants reported doing more activities with their infants at 10 months. These results suggest that the fathers who most need support to become more involved with their children are likely to be those who are the most difficult to get involved in an EHS program. ©2002 Michigan Association for Infant Mental Health.