Leg weakness in broiler chickens was assessed when the birds were different ages and housed at different stocking densities (STD). Two trials were conducted. In trial 1, birds were housed at the following stocking densities: 833, 625, or 435 cm2 per bird. The walking ability of the birds was assessed at 28, 42, and 49 days of age. In trial 2, the following stocking densities were studied: 625 or 455 cm2 per bird. Tibial dyschondroplasia (TD) was assessed in the birds at 28 days of age and walking ability was assessed at 35 days of age. When the birds were slaughtered at 42 days of age, foot pad burn, hock burn, and angulation of the hock joint were assessed. During both trials, body weight was also measured. The results indicated that leg weakness was not a problem at 28 days of age at any of the STD. Leg weakness deteriorated over the next two weeks, such that the birds had more difficulty walking. Walking ability continued to worsen in the following weeks. Leg weakness was a greater problem in males than females. The results from both trials indicated that greater difficulties walking and reduced live weights occurred at higher stocking densities. More hock and foot burns were occurred in birds at higher stocking densities. However, stocking density did not have an effect on TD or angulation of the hock joint. The authors concluded that leg weakness was reduced at lower STD.