This review examines the intricate association between maternal immune activation (MIA) and autism spectrum disorder (ASD), emphasizing the impact of maternal infections during pregnancy. Epidemiological studies link viral and bacterial infections to an elevated risk of ASD, revealing the complex interplay between environmental factors and neurodevelopmental outcomes. Immunological mechanisms, including cytokine dysregulation and neuroinflammation, involve key players such as interleukin-6 and tumor necrosis factor-alpha, influencing fetal brain development and ASD risk. Genetic and environmental interactions contribute to individual susceptibility, with specific variants influencing MIA's impact on ASD risk. Epigenetic modifications provide a molecular link between environmental exposures, including MIA, and enduring neurodevelopmental changes. Recognizing critical periods during fetal neurodevelopment susceptible to MIA is crucial. Long-term studies highlight enduring consequences on behavior and cognition into childhood and adolescence. Exploring potential therapeutic interventions, including immunomodulatory strategies during pregnancy, offers hope for mitigating MIA's impact on ASD outcomes. Despite progress, knowledge gaps persist, motivating future research guided by emerging technologies and interdisciplinary approaches to unravel the intricate MIA-ASD relationship.