Introduction: Leaves are among the most plastic organs in plants, and their structure, while shaped by phylogeny, can show considerable phenotypic plasticity within a species in response to environmental gradients. Monstera deliciosa, a tropical hemiepiphytic vine known for high leaf heteroblasty, adapts to diverse light conditions. This makes leaf structure a useful proxy for assessing whole-plant resource allocation strategies and adaptations to environmental changes. Objective: To measure the morphological and structural differences in sun and shade leaves using nine leaf traits (petiole length, leaf width and length, effective leaf area, fenestrated area, leaf perimeter, lobulation ratio, stomatal density, and specific leaf area -SLA-). Methods: We selected 20 widely separated M. deliciosa plants on the University of Costa Rica campus in 2022, positioned in contrasting sun and shade conditions, and measured one mature leaf per plant (ten per light environment). Results: Sun leaves had higher fenestrated area, perimeter, and stomatal density, suggesting structural adaptations to high light. These traits may enhance thermal regulation by facilitating heat dissipation. Sun leaves had lower SLA, indicating thicker, denser leaves better suited to high light and wind exposure. Lobulation ratios (leaf dissection) were not different between sun and shade conditions. A principal component analysis explained 82.88% of the variation in the leaf traits, with 39 % of the variation attributed to fenestrated area, leaf perimeter, and effective leaf area. Correlation analyses showed that fenestrated area, perimeter, and stomatal density were positively associated (and negatively related to SLA), emphasizing the functional convergence of these traits, adapting the leaf phenotype to light differences. Conclusions: M. deliciosa modulates leaf morphology and structure to adapt to distinctive light conditions, with fenestration, stomatal density, and SLA emerging as crucial traits. These findings underscore the significance of environmental differences in driving leaf shape and structure.