A study was conducted to evaluate the effects of healthy broiler breeder undefined cecal culture and commercial probiotic (PremaLac®) on broiler performance and the serum lipids of broiler chickens from 1-42 days of age. A total of 288 days old Ross male broiler chickens were used in a 3x2 factorial arrangement with three levels of cecal cultures (0.00, 2.50, 5.00 mL L-1 in drinking water) and two levels of PremaLac (0.00, 0.09% in the diet). The cecal cultures and PremaLac were used >7 days of age. Body weight gain was significantly increased in cecal culture-inoculated compared to control broilers at the critical period of 0-21 days of age. A higher body weight gain was also observed in PremaLac-treated compared to control broilers for the whole growing period of 0-42 days. The feed intake and feed conversion ratio decreased in PremaLac-fed compared to control broilers from 0-21 days of age. Cecal cultures and PremaLac did not decrease serum lipid components. More research is needed to clarify the beneficial or adverse effect of cecal cultures as probiotics in poultry.