This study investigates the effects of willow (Salix spp.) leaf powder supplementation on growth performance, hematological parameters, biochemical profile, and histological liver changes in local male rabbits (Oryctolagus cuniculus). Twenty-four rabbits (1.5–2 months old, 1.2 ± 0.2 kg) were randomly assigned into three groups: a control group, and two experimental groups receiving 4 g/kg and 5 g/kg of willow leaf powder, respectively. The feeding trial lasted six weeks, during which feed intake and body weight were recorded. Hematological indices (Hb, RBC, WBC), biochemical parameters (glucose, urea, triglycerides, total protein, albumin, globulin), liver enzymes (GOT, GPT), and carcass traits were analyzed using standard procedures. Results indicated that willow supplementation significantly improved final body weight and feed intake, particularly at 4 g/kg. Hematological parameters showed no significant adverse effects, while triglycerides and total protein were significantly increased in the 5 g/kg group. Liver enzyme activity remained largely stable across groups. However, histological examination revealed mild to moderate hepatic alterations at the higher dose. Overall, willow leaf powder demonstrated positive effects on growth and metabolic status, with optimal benefits observed at 4 g/kg. Nevertheless, higher inclusion levels may induce hepatic stress. These findings suggest that willow leaf powder is a promising phytogenic feed additive for rabbit production, though dosage optimization is essential for safe application.