Plastic production has grown rapidly worldwide, yet the health impacts of exposure to microplastics (1–5 mm fragments from degraded or manufactured plastics) remain poorly understood. Research suggests that microplastics may damage internal tissues and affect organism health. This study examines whether microplastic ingestion influences waterbird condition and tests for correlations between ingestion levels and physiological health indicators. We used the percentage of gastrointestinal (GI) tract fat as a proxy for body condition, as these reserves are among the last mobilized during starvation. Dabbling and diving duck carcasses were donated by hunters across Louisiana during the 2013–2014 hunting season, and American Woodcock (Scolopax minor) were collected during the 2023–2024 season. GI tracts were removed and weighed with and without associated fat to determine percent fat. To quantify microplastic ingestion, GI contents were digested in 10% KOH, filtered to isolate 1–5 mm particles, and examined under a dissecting microscope. Dabbling duck species exhibited higher concentrations of microplastics than diving ducks or woodcocks. Within dabblers, we found a negative correlation between percent GI fat and microplastic concentration, suggesting that higher ingestion may be associated with poorer condition. No relationship was detected in diving species or woodcocks. These findings contribute to understanding how microplastic exposure may affect waterbirds in Louisiana and may help inform future plastic pollution policy.