Using MACRO forms, ratings of 110 mother-infant and 85 mother-toddler consecutive admissions to a South Australian psychiatric inpatient mother-infant unit provided data on internal consistency, inter-rater reliability, and test-retest reliability. Internal consistency was between 0.79 and 0.95 for all MACRO domains. Item total correlations were between 0.39 and 0.90, with the exception of one item related to social support. Test-retest reliability after 7 days was 0.71 or above. The authors conclude preliminary psychometric investigations of the MACRO are favorable. If further validity investigations prove satisfactory, the MACRO will provide a valuable clinical and research tool. It offers a convenient framework for assessing risk and interpreting the impact of maternal mental illness on children in a context that permits consideration of such factors as illness severity, parenting practices, and child contribution to outcome. Case vignettes are included, and a brief description of the two MACRO forms is appended. 54 references, 5 tables, and 2 figures