Severe mental illnesses (SMIs) can affect parents' ability to provide an adequate environment for their children. Little has been written about the different factors that affect these abilities in individuals with SMI. In this study, we explored a number of relationships that have been found in the literature to be related to parenting styles. Our main hypotheses were that the participants' secure attachment with their parents is positively correlated with high levels of social support; social support is positively correlated with the experience of having good parental competency; lack of parental competency is negatively correlated with problematic parenting styles. This correlational and cross‐sectional study was conducted with 60 mothers with SMI. Results suggest a strong relationship between parental style, sense of parental competency, social support and attachment style of the parent. Negative parental styles were found to be negatively correlated with parental competence. Overactive and hostile parenting styles were found to be correlated with the interviewees' parental overprotecting attachment style. Positive correlations were found between parental competence and high social support. The results of the study may help in developing future multidimensional interventions for parents with SMI, to improve their parenting skills and reduce any negative influence on their offspring.