Background: The first aim of the present study was to estimate the extent to which differences in well-being in parents of children with and without intellectual disability (ID) in Sweden can be accounted for by differences in the presence of the risk factors: (1) child disability; (2) socioeconomic disadvantage; (3) household composition; and (4) parental characteristics. The second aim was concerned with individual variation in well-being within the group of parents of children with ID. The aim was to estimate if protective factors such as parental personality characteristics (sense of coherence), perceived positive impact of the child and satisfaction with participation in different arenas of life explained variation in well-being in mothers and fathers of children with ID over and above that explained by the risk factors. Method: Parents of children with ID (62 mothers and 49 fathers) and control children (183 mothers and 141 fathers) completed postal surveys on well-being, socioeconomic situation, health, sense of coherence, satisfaction with participation in different arenas of life and the child's impact on the family. Results: The results showed that mothers of children with ID had lower levels of well-being than fathers and control parents, but the presence of a child with ID did not in itself predict poorer maternal well-being. Rather, differences in economic hardship and self-rated health were the strongest predictors for well-being. It was further found that 67.7% of the mothers of children with ID scored within the high well-being group. The predictive power of the model increased significantly for both fathers and mothers when protective factors were added to the model (42 and 78% explained variance compared with 25% with only risk factors). Conclusions: Well-being of parents with a child with ID is dependent upon the interplay of risk and protective factors and research needs to address these variables simultaneously.