Administrative data from adult Medicaid, income maintenance, and child welfare databases were combined to examine whether there is an association between maternal substance abuse and dependence and the risk of having a substantiated report of child maltreatment in Missouri. Only maternal perpetrators of maltreatment were included. The 40,567 women in the study had one or more live births during the years 1987-1992 and were followed for eight years after giving birth. They received public assistance for at least part of the eight-year period. In the sample, 1,359 women had a Medicaid service use record of treatment for substance abuse or dependence, while 39,208 did not. Maternal depression (determined by a Medicaid service use record for treatment), maternal age at time of first of only live birth, maternal race, and residence (urban or rural) at time of giving birth were controlled. Multivariate statistics were run using Cox Proportional Hazards models. There were 7,041 women with a substantiated report of any maltreatment, and 1,368 reports of physical abuse, 449 of sexual abuse, 5,907 of neglect, 370 of emotional maltreatment, and 574 of other maltreatment. Maternal substance abuse or dependence increased the risk of having a substantiated report of all types of child maltreatment except sexual abuse. Maternal depression increased the risk of having a substantiated report for all types of maltreatment. Maternal age, maternal race, residence, and the interactions of time and certain variables were significant for some types of maltreatment but not for others. The largest number of substantiated reports was for neglect. Implications include 1) analyzing types of maltreatment separately, since in this study each type had different significant variables associated with it; 2) the necessity for better definitions of abuse and neglect, especially emotional maltreatment; 3) the need to look more closely at substance abuse and dependence and neglect, given the large number of cases of neglect and significant increase in risk when substance abuse or dependence is present; 4) examining the overlap between substance abuse and dependence and depression; and 5) the availability of treatment for substance abuse and dependence and depression.