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The aim of the present study was to estimate the genetic improvement in the last recurrent selection cycles applied in two ’Valenciana’ onion populations in Petrolina, PE. The experiments were carried out between October 2014 and January 2015, in Petrolina and Juazeiro, BA. The experiment consisted of a randomized block design, with 12 treatments and three replications. Analyses of variances were carried out separately for each population. The control population CNPH6400 was the comparison basis. Heritability and genetic gain were estimated for total (Prototal) and commercial (Procom) bulb yields. Significant differences were observed for Prototal and Procom in both populations and in both environments, except for the 25CA10 population, in Juazeiro. The highest Procom genetic gains were observed in Petrolina for 25CA10 and T811CR13 populations (510.5% and 522.1%, respectively), proving the efficiency of recurrent selection cycles. Genetic gains were nonlinear, and fluctuations may have occurred due to genetic drift.