Abstract: The objective of this study was to determine effect of dietary phosphorus (P) on P utilization and excretion in Thai-indigenous heifers. The experimental design was a 4x4 Latin square design with 21 day period. Four Thai-indigenous heifers, average body weight of 107±4.53 kg, were randomly received 1 of 4 diets containing 0.10, 0.20, 0.30 and 0.40% P at 2% of BW. The results found that feed intake and nutrient digestibility of heifers were not significantly different (p>0.05) among treatments. Intake of P, P excretion, P absorption, P retention and plasma P concentration significantly increased (p < 0.05) with increasing dietary P. Additionally, P absorption and P retention of heifers fed 0.30 % dietary P were not significantly different (p>0.05) with those of heifers fed 0.40% dietary P. Based on the results, it could be concluded that dietary P levels affected significantly (p < 0.05) P utilization and excretion in Thai-indigenous heifers. The P requirement of heifers was lower than 0.4% of diet.