Purpose Autism spectrum disorders (ASD) are heterogeneous disorders, and heterogeneity lies both at genetic and phenotypic levels. To better understand the etiology and pathway that may contribute to autism symptomatology, it is important to study milder expressions of autism characteristics – autistic traits or milder expressions of autism phenotype, especially in intergenerational context. This study aims to see the trend of association, if any, between child autism symptom and mothers’ autism phenotype as well as mothers’ theory of mind and to see if mothers’ theory of mind was associated with their own autistic traits. Design/methodology/approach Data were collected from 96 mothers of children with varying symptom severity of autism (mild, moderate and severe) using Autism Spectrum Quotient and faux pas recognition test. Analysis of variance, trend analysis and t-test were done. Findings Results showed a linear trend of relationship between mothers’ autism phenotype and child symptom severity. However, the groups did not have significant differences in theory of mind. Only a few components of theory of mind were found to be associated with autistic traits. These findings question the prevailing idea that theory of mind can be a reliable endophenotype of autism. Research limitations/implications There has been a lack of research assessing the possible link between parents’ autism phenotype and symptom severity of ASD children. This study is a preliminary step towards that direction. This study indicates a probability of shared genetic liability between mothers and offspring, which would have important consequences for understanding the mechanisms that lead to autism. Practical implications This study offers implications for treatment planning of those with clinical ASD. An awareness of parental factors is critical for any holistic intervention plan when a family seeks treatment for their child. This study suggests that while individualising interventions, clinicians may consider possible presence of high levels of autistic traits and related cognitive features present in the probands’ parents. Originality/value There has been lack of research assessing the possible link between parents’ autism phenotype and symptom severity of ASD children. This study, even though preliminary, is a step towards that direction. This study suggests that autism traits might be influenced by common genetic variation and indicates a probability of shared genetic liability between mothers and offspring, which would have important consequences for understanding the mechanisms that lead to autism.