Objective: Maladaptive daydreaming (MD) is characterized by vivid, excessive fantasy activity that becomes prioritized over other activities and may result in avoidant coping strategies. Little is known about the relationship between MD and internalized stigma in the neurodivergent sample. The current study aimed to examine emotional dysregulation, escapism and self-perception (self-esteem and internalized stigma) as potential determinants of MD in three groups: adults on the autism spectrum, with ADHD, and both diagnoses ("AuDHD"), including their neurodivergent symptoms (autistic traits, empathizing, ADHD symptoms). Methods: A sample of 293 persons (139 with ADHD, 74 on the autism spectrum, and 80 with both diagnoses) completed self-report scales concerning ADHD symptoms, autism spectrum symptoms, empathizing, self-esteem, daydreaming as escapism, emotional dysregulation, maladaptive daydreaming, and internalized stigma. A correlation analysis was implemented. Additionally, a group comparison and quantile regression for the 25th, 50th, and 75th percentile of maladaptive daydreaming in the three groups were executed. Results: The results showed that internalized stigma, emotional dysregulation, escapism, and self-esteem have significant associations with MD in the neurodiverse sample. The ADHD group achieved the lowest scores in emotional dysregulation, discrimination experience, and social withdrawal. The groups did not vary in MD rates, stereotype endorsement, stigma resistance, nonacceptance of emotional responses, and impulse control difficulties. The AuDHD group achieved higher results than the ASD group only in the ADHD symptoms. Quantile regression revealed differences in the predictors of maladaptive daydreaming in the three groups. ADHD symptoms and self-suppression escapism were significant predictors for the higher levels of MD in persons with singular autism or ADHD diagnosis. Conclusion: The results showed no differences in MD rates, although there were significant variations in predictive features among the three samples. The role of internalized stigma and self-esteem was highlighted in the results as significant associates of MD prevalence. These outcomes expand the current knowledge in the context of maladaptive daydreaming, internalized stigma, self-esteem and emotional dysregulation in a neurodiverse sample and allow for proposing clinical applications and further research directions.