Replacing traditional di-calcium phosphate (DCP) with nano-hydroxyapatite (NHA) was investigate as a potential strategy to enhance mineral bioavailability and reduce feed costs. This study explored the impact of varying levels of dietary NHA on broiler chicks' growth performance, carcass traits, digestive tract measurements, and immune organs. A total number of 1080 unsexed one-day-old "Cobb 500" broiler chicks were distributed in a completely randomized design of six treatments with three replicates (60 chicks each). The control group (T1) contained 100% DCP of diet, treatments two (T2) to six (T6) were supplemented with NHA, which represent replacement rates of 100, 80, 60, 40 and 20% of DCP in the basal diet, respectively. The results indicate that broilers fed with 100% DCP demonstrated superior growth performance and carcass weight (P≤0.05) compared to those receiving lower NHA dosages. Specifically, the 100% DCP group achieved higher carcass weight (P≤0.05), while diets containing 80% NHA substitution for DCP resulted in higher carcass percentages. In contrast, birds on lower NHA diets (60 and 40%) exhibited higher giblet percentage (P≤0.05), and lower (P≤0.05) abdominal fat weights were observed at 40% NHA levels. The control group with 100% DCP had a significantly higher (P≤0.05) relative gut weight compared to other treatments. The spleen percentage was notably highest in the group receiving 100% NHA and NHA significantly increased thymus weight and percentage, especially T4, with similar improvements in groups T3, T4, T5, and T6. Additionally, birds fed 40% NHA showed a notable increase in the relative weight and percentage of the bursa compared to other groups. In conclusion, while NHA offer potential benefits in broiler chicken nutrition; further research are needed to determine the optimal dosage, specific conditions, sustainable and environmentally friendly options for incorporating these nanoparticles into broiler chicken feed.