Background <p>Autism spectrum disorder (ASD) is a neurodevelopmental condition characterized by deficits in social communication and interaction, and repetitive behaviors. Males are three times more likely to be diagnosed with ASD than females, and sex-dependent alterations in behavior and communication have been reported both in clinical and animal research. Animal models are useful for understanding ASD-related manifestations and their associated neurobiological mechanisms. However, even though ASD is diagnosed during childhood, relatively few animal studies have focused on neonatal development.</p> Methods <p>Here, we performed a detailed analysis of neonatal developmental milestones and maternal separation-induced ultrasonic vocalizations (USVs) in two genetic animal models of ASD, neurofibromatosis type 1 (<i>Nf1</i>^±) and tuberous sclerosis complex 2 (<i>Tsc2</i>^±).</p> Results <p><i>Nf1</i>^± and <i>Tsc2</i>^± mice display strikingly distinct developmental profiles regarding motor, strength, and coordination skills. <i>Nf1</i>^± mouse pups mostly show genotype-related differences, whereas <i>Tsc2</i>^± mouse pups mainly present sexual dimorphisms. Furthermore, we found several differences regarding the number of USVs, frequency modulation, and temporal and spectral profile. Importantly, <i>Nf1</i>^± animals tend to present sex- and genotype-dependent differences earlier than the <i>Tsc2</i>^± mouse pups, suggesting distinct developmental curves between these two animal models.</p> Conclusions <p>This study provides a nuanced understanding of how these two ASD models differ in their developmental trajectories. It underscores the importance of studying sex differences and early-life developmental markers, as these could offer crucial insights into ASD's progression and neurobiology. The distinct profiles of these models may help guide more targeted therapeutic strategies in the future.</p>