Objective A higher rate of depressive symptoms is found among mothers of children with disabilities compared to other parents. However, there is a lack of study of mothers with children <3 years of age participating in Early Intervention (EI) programs. This study aims to more fully describe the extent of mood disorders in these mothers including estimated prevalence, severity and factors associated with maternal mental health, using gold standard clinical diagnostic and symptom measures, and test models associating depressive symptoms with contextual factors and child behavior. Methods A cross-sectional study was conducted with 106 women who had at least one child enrolled in EI. Mothers were interviewed and completed reliable, valid measures to evaluate mental health, health status, family conflict, parent-child interaction, self-efficacy, social support, child behavioral problems, hardship, endangerment, and child disability. Descriptive statistics and multivariate analyses were performed. Results We found 8 % of participants met all criteria for a Major Depressive Episode (MDE) with 44 % of the sample reporting a past episode and 43 % endorsing recurrent episodes. Using the CES-D to assess depressive symptom severity approximately 34 % of mothers screened in a clinically significant range. Using linear regression to predict severity of current depressive symptoms demonstrated that current depression severity was primarily predicted by poorer maternal health status, lower self-efficacy and past MDE (p < 0.05). Conclusions for practice A brief assessment of maternal mood, health and self-efficacy are important factors to assess when evaluating how to support mothers of children in EI.