The effect of tetracycline HCl and oxytetracycline HCl on early mortality in straight-run Peterson x Hubbard cross broiler chicks from 28-wk-old dams was studied. Treatments consisted of a sham-treated control, and groups treated with a tetracycline either HCl (25 mg/454 g of BW per day) or an oxytetracycline HCl (14.6 mg/454 g of BW per day). Each group was treated via the drinking water for the first 5 days after hatching. There were 24 replications per treatment with 54 chicks each. Birds were maintained at a density of 622.5 cm2 per chick. Chicks treated with tetracycline HCl and oxytetracycline HCl had significantly (P less than .05) improved livability when compared with the sham-treated controls both at 2 and 6 wk of age (1.00 and .83 versus 1.79 at 2 wk, and 2.79 and 3.29 versus 4.29% mortality at 6 wk, respectively). No significant differences in mortality were observed between tetracycline HCl-treated chicks and oxytetracycline HCl-treated chicks. At the end of the 6-wk trial, no differences between treatments were seen in the productive performance of the broilers. The observed differences in livability at 6 wk of age could increase the number of saleable broilers by 10 to 15 thousand per million chicks placed.