Background and Aim: The rearing of quails can have a stronger attraction for the breeders if we lower the cost prices by introducing by-products in their feed formulas. The aim of this study was to evaluate the effects of the partial substitution of soybean meal by apricot kernel cake (AKC) in the diet of quails, applied either sequentially or during all phases of rearing, on their growth performances, carcass characteristics, and meat physicochemical composition. Materials and Methods: A total of 600 one-day-old quails (Coturnix coturnix japonica), with equal sex ratio and weighing on average 7[+ or -]0.2 g, were randomly distributed in one control group and three experimental groups, the latter being designed according to the rate of application of AKC in either sequential or non-sequential mode in different rearing phases. Each group was divided into five replicates of 30 quails, randomly distributed according to either substitution rate of soybean meal by the AKC (0%, 10%, 20%, or 30%) or farming phase. Results: The average daily gain from the 1st to 45th days ([average daily gain.sub.1-45d]) was found to be the highest (4.24 g/d/subject, p=0.021) for the 30% AKC-supplemented feed lot in either starter or finish incorporation ([DF.sub.TAA]), having an optimum final live weight of 193.4 g (p=0.028), a lowest feed conversion ratio of 3.08 (p=0.001), and a daily feed intake of 860 g (p=0.01). Carcass yield was recorded the highest (74.4%, p=0.02) with an optimum meat protein level (30.6%, p=0.024) and the lowest fat content (2.26%, p=0.001) for the same group as well. Conclusion: The partial substitution of soybean meal by AKC in the quails' fattening feeding, during the finishing phase and for all rearing phases, led to a better growth performance, a better carcass yield, and an improved chemical composition of meat. Keywords: by-products, carcass, feed, growth performance, quails.