An experiment was conducted to determine the effects of an organic acid combination (Acid Lac Dry: lactic, fumaric, propionic, citric and formic acid) and/or zinc bacitracin on the body weight gain, feed efficiency, microflora and pH in the ileum content of broiler-type chicks. Ross PM3 broiler chicks were placed in an experimental design that consisted of four dietary treatments with 48 broilers in each group. One-day-old chicks were fed either a control diet or a similar diet supplemented with 3 g/kg Acid Lac Dry, 0.1 g/kg zinc bacitracin or both additives in combination during a 42-d feeding trial. Add Lac Dry+zinc bacitracin supplemented diet, significantly (P<0.05) increased body weight at 3 weeks of age but not at 6 weeks of age when compared with control and Acid Lac Dry supplemented diets. The best feed to gain ratio was obtained in group fed Acid Lac Dry+zinc bacitracin supplemented diet during this experiment. Carcass weight and dressing percentage were not affected by any treatment Mean ileal pH was significantly (P<0.05) higher in group fed the additives in combination than the animals treated with either Acid Lac Dry or zinc bacitracin. However, the combination had the lowest number of Enterobacteriaceae in the intestinal material.