Ego development, the capacity to derive coherent, nuanced meaning from one’s life experiences, often has significant impact on psychosocial adjustment during adulthood. Research with nonclinical populations has indicated links between higher ego development and healthy emotional coping and interpersonal relationships. Emerging research with substance-abusing mothers suggests that higher levels of ego development are associated with improved parenting but also with increased rates of psychopathology. Less is known about how ego development is related to other psychosocial factors important for substance-abusing mothers’ functioning and capacity to parent, including the proclivity to engage in risky behaviors, adaptive coping behaviors, and readiness to engage in psychotherapy. The present study examines these links. Participants included 182 methadone-maintained women who expressed interest in a randomized clinical trial testing the efficacy of a relational parenting intervention for substance-abusing mothers (Luthar, Suchman, & Altomare, 2007). Data were analyzed using a series of MANCOVAs and ANCOVAs controlling for maternal IQ and depression. Mothers with higher levels of ego development reported more adaptive coping techniques and greater readiness to engage in psychotherapy but also reported a heightened desire for strong sensations. Findings are discussed in light of mothers’ psychological processes and parenting capacities. The significance of findings for developing parenting interventions for substance-abusing mothers is also discussed.