Aim: To analyze the multiple factors affecting the risk of maltreatment in young children within a comprehensive theoretical framework. Methods: The research is based on a large UK cohort study, the Avon Longitudinal Study of Parents and Children. Out of 14,256 children participating in the study, 293 were investigated by social services for suspected maltreatment and 115 were placed on local child protection registers prior to their 6th birthday. Data on the children have been obtained from obstetric data and from a series of parental questionnaires administered during pregnancy and the first 3 years of life. Risk factors have been analyzed using an hierarchical approach to logistic regression analysis. Results: In the stepwise hierarchical analysis, young parents, those with low educational achievement, and those with a past psychiatric history or a history of childhood abuse were all more likely to be investigated for maltreatment, or to have a child placed on the child protection register, with odds ratios between 1.86 and 4.96 for registration. Examining strength of effect, the highest risks were found with indicators of deprivation (3.24 for investigation and 11.02 for registration, after adjusting for parental background factors). Poor social networks increased the risk of both investigation (adjusted OR 1.93) and registration (adjusted OR 1.90). Maternal employment seemed to reduce the risk of both outcomes but adjusted odds ratios were no longer significant for registration. After adjusting for higher order confounders, single parents and reordered families were both at higher risk of registration. Reported domestic violence increased the risk of investigation and registration but this was no longer significant after adjusting for higher order variables. Low birthweight children were at higher risk of registration as were those whose parents reported few positive attributes of their babies. Conclusions: This study supports previous research in the field demonstrating that a wide range of factors in the parental background, socio-economic and family environments affect the risk of child maltreatment. By combining factors within a comprehensive ecological framework, we have demonstrated that the strongest risks are from socio-economic deprivation and from factors in the parents' own background and that parental background factors are largely, but not entirely, mediated through their impact on socio-economic factors.