During the first year of life, infants spend substantial amounts of time exploring objects they encounter in their daily environments. Perceptuo-motor information gained through these experiences provides a foundation for later developmental advances in cognition and language. This study aims to examine developmental trajectories of visual, oral, and manual object exploration in infants with and without risk for autism spectrum disorder before the age of 1 year. A total of 31 infants, 15 of whom had an older sibling with autism and who were therefore at heightened risk for autism spectrum disorder, played with sounding and nonsounding rattles at 6 and 9 months of age. The results suggest that heightened-risk infants lag behind their low-risk peers in the exploration of objects. The findings are discussed in terms of how delays in object exploration in infancy may have cascading effects in other domains.