Background Given the great benefits of effective parenting to child development under normal circumstances, and the even greater benefits in the face of risk, it is important to understand why some parents manage to be effective in their interactions with their child despite facing formidable challenges. This study examined factors that promoted effective parenting in the presence of child developmental delay, high child behaviour problems, and low family income. Method Data were obtained from 232 families at child age 3 and 5 years. Using an adapted ABCX model, we examined three risk domains (child developmental delay, child behaviour problems, and low family income) and three protective factors (mother's education, health, and optimism). The outcome of interest was positive parenting as coded from mother–child interactions. Results Levels of positive parenting differed across levels of risk. Education and optimism appeared to be protective factors for positive parenting at ages 3 and 5, and health appeared to be an additional protective factor at age 5. There was an interaction between risk and education at age 3; mothers with higher education engaged in more positive parenting at higher levels of risk than did mothers with less education. There was also an interaction between risk and optimism at age 3; mothers with higher optimism engaged in more positive parenting at lower levels of risk than did mothers with less optimism. The risk index did not predict change in positive parenting from age 3–5, but the protective factor of maternal health predicted positive changes. Conclusions This study examined factors leading to positive parenting in the face of risk, a topic that has received less attention in the literature on disability. Limitations, future directions, and implications for intervention are discussed.