<p>Pharmaceutical residues persist in water systems worldwide because of widespread use and incomplete degradation during treatment at wastewater treatment plants. Such processes often fail to remove trace levels of pharmaceuticals completely, allowing contaminants to enter rivers and lakes. Numerous studies have addressed toxicity, yet specific effects on aquatic organisms, such as fish, remain poorly understood. Carbamazepine is frequently detected in aquatic environments, highlighting the need for focused research. This work examines the neurological implications of exposure to sublethal concentrations of carbamazepine in zebrafish (<i>Danio rerio</i>), a widely used model in aquatic toxicology. Brain activity was monitored as a complementary functional endpoint alongside behavioral assays of cognitive performance and locomotion. Findings indicated a marked increase in cognitive abnormalities following exposure, suggesting that carbamazepine can disrupt neurological processes in zebrafish. This evidence supports the development of novel toxicity evaluation frameworks that accurately capture ecological risk from pharmaceutical contaminants. Employing zebrafish behavior as an indicator offers a promising approach for toxicity assessment. Insights gained aim to inform strategies that mitigate ecological impacts of pharmaceutical pollution and actively support safeguarding healthy aquatic ecosystems.</p>