Emerging evidence suggests that motor and language delays are prevalent developmental concerns in young autistic children. Nonetheless, it is not well understood how these co-occurring conditions of autism spectrum disorder (ASD) relate to each other during the later childhood of autistic children. This study aimed to elucidate influential factors of motor and language/literacy development in school-aged autistic children from parental perceptions using in-depth semi-structured interviews. Ten mothers (Mage 37.5 ± 5.9) of autistic children (Mage 9.6 ± 1.6) participated in the individual interviews via video conference or phone calls with a particular focus on individual characteristics, parental involvement, and learning environment for motor and language/literacy development in their child. Open and axial coding was conducted, and salient themes were discussed until consensus was reached. The identified themes were categorized into two focal points, including 1) general parental attitudes toward their child’s learning and development and 2) parental self-efficacy manifesting in response to individual variations (e.g. difficulty with fine motor and coordinated skills and unique autistic traits) and environmental constraints (e.g. lack of resources and limited systematic support for sustainable care) that affect their child’s fundamental skills development. Concept maps were sequentially generated to visualize the connections among influential factors for both typical and delayed motor and language/literacy development in autistic children. Further studies with objective skills assessments and triangulated multi-informant data from other key stakeholders of ASD are warranted to delineate the association between motor, language, and literacy development in school-aged autistic children.