The aim of this study was to investigate the effects of different levels of cadmium supplementation (0, 5, 10, 20, 40 and 80 mg/kg) in the diet on performance, egg quality, tibia biomechanical properties and eggshell and bone mineral contents in laying quails. In this 10-week trial, a total of 96 laying quails, aged 21 weeks, were randomly distributed among six experimental groups. Each experimental group contained four replicates of four birds each. The performance parameters were adversely affected quadratically when cadmium was added to the diets in the concentrations of 20 mg/kg and above (P<0.01). The specific gravity and eggshell weight were maximal with the addition of 20 mg/kg cadmium to the diet. The biomechanical properties of the tibia were negatively affected by cadmium supplementation in quails (P<0.05). The eggshell boron content decreased linearly (P<0.001) with cadmium supplementation to the diet. The cadmium content in bone increased when cadmium was added to the diets (P<0.001). The bone boron concentration decreased as dietary cadmium supplementation was increased (P<0.001).