<p>Environmental literacy plays a critical role in fostering environmentally responsible behaviors and supporting sustainable development. However, many environmental education programs implemented in primary schools remain limited in scope and rarely address emerging environmental challenges such as pharmaceutical pollution. This study examined short-term changes in environmental literacy following a multimodal, play-based environmental education intervention designed for primary-school students. The intervention was implemented with 84 fourth-grade students and focused on four thematic domains: water conservation, recycling, solid-waste management, and proper medication disposal. The educational program combined storytelling, puppet theater, experimental demonstrations, and participatory classroom discussions to translate environmental concepts into age-appropriate learning experiences. The intervention was conducted within a quasi-experimental pre–post design under regular school conditions. Environmental literacy was assessed using a previously validated questionnaire administered before and after the six-month intervention. Baseline results revealed substantial gaps in environmental literacy, with average scores below 30% correct responses across most domains. Following participation in the intervention, environmental literacy scores increased significantly in all thematic areas. Water conservation improved from 15.4% to 63.5% (<i>t</i> = 11.56, <i>p</i> &lt; 0.001), recycling from 7.7% to 50.0% (<i>t</i> = 8.90, <i>p</i> &lt; 0.001), solid-waste management from 28.2% to 68.8% (<i>t</i> = 9.47, <i>p</i> &lt; 0.001), and medication disposal from 23.1% to 60.0% (<i>t</i> = 8.01, <i>p</i> &lt; 0.001). The overall environmental literacy score increased from 18.8% to 61.0% (<i>t</i> = 22.70, <i>p</i> &lt; 0.001). These improvements reflect increased understanding of everyday environmental practices related to water use, waste management, and responsible medication disposal. Regression analysis indicated that baseline environmental literacy (β = 0.65, <i>p</i> &lt; 0.001) and maternal education level (β = 0.21, <i>p</i> = 0.031) were significantly associated with post-intervention environmental literacy scores. These findings suggest that environmental literacy improved following participation in a multimodal environmental education intervention. Given the quasi-experimental design, the results should be interpreted as short-term educational gains rather than definitive causal effects. Integrating topics such as pharmaceutical pollution and medication disposal into environmental education programs may represent a promising and contextually relevant approach for addressing emerging environmental challenges through early environmental learning.</p>