Purpose <p>What is observable in children on the autism spectrum is not only a specific developmental dynamic of temperamental profiles but also the contribution of sensory responsiveness to explaining the level of their temperamental traits. The aim of the conducted research was to determine whether the associations between temperamental traits and sensory responsiveness differed in two groups of children on the autism spectrum: younger (aged between 3 and 6&#xa0;years) and older (aged between 7 and 11&#xa0;years).</p> Method <p>A group of 394 children diagnosed with autism was investigated: 208 aged between 3 and 6&#xa0;years, and 186 aged between 7 and 11&#xa0;years. The following tools were used: Sensory Experiences Questionnaire 3.0-Polish Version, and EAS-C Temperament Questionnaire.</p> Results <p>The results indicate that the level of temperamental traits in the participating children is determined by the level of various dimensions of sensory responsiveness—to a greater extent in younger children than in older ones. The moderating role of age can be seen in the association of sociability with sensory hyporesponsiveness. In turn, sensory hyperresponsiveness and sensory seeking are associated with activity and shyness in both age groups.</p> Conclusion <p>It can therefore be concluded that in the group of younger children on the autism spectrum, more aspects of temperament can be explained by the dimensions of sensory responsiveness than in older children.</p>