Recent research has suggested that mothers participating in home visitation programs have a high incidence of mental health problems, particularly depression. Posttraumatic stress disorder (PTSD) is a common comorbidity with depression, yet its prevalence among home visiting populations and implications for parenting and maternal functioning have not been examined. This study contrasted depressed mothers with (n = 35) and without PTSD (n = 55) who were enrolled in a home visitation program. Results indicated that depressed mothers with comorbid PTSD were more likely to have experienced childhood sexual abuse, had greater severity of depressive symptoms, increased social isolation, and lower overall functioning than their counterparts without PTSD. Among PTSD mothers, greater severity of PTSD symptoms, in particular avoidance and emotional numbness, were associated with increased maternal psychopathology and parenting deficits even after controlling for depression severity. These findings add to the literature documenting the negative impacts of PTSD on maternal functioning and parenting. Implications for screening and treatment in the context of home visitation are discussed.