Abstract The climatic and edaphic conditions of the semi-arid Brazilian Northeast region limit the production of several annual crops, including cotton. The aim of this study was to estimate the genetic parameters and select water stress tolerant cotton lines based on yield and fiber quality traits. Twenty cotton lines were evaluated in Alagoinha-PB over two years under rainfed conditions. Individual and joint analysis of variance was performed on the data. Genetic parameters were determined, and lines were selected using the selection index. The lines CNPA SA 2019-115, CNPA SA 2019-185, CNPA SA 2019-109, and CNPA SA 2019-165 were selected for further tests in the region for recommendation of new cultivars. These lines can form new blocks of crosses, together with the BRS 286 check cultivar, as they have the best mean yield and fiber quality values, with the expectation of significant genetic gains. semiarid semi arid crops traits AlagoinhaPB Alagoinha PB data determined index 2019115, 2019115 2019 115, 115 2019-115 2019185, 2019185 185, 185 2019-185 2019109, 2019109 109, 109 2019-109 2019165 165 2019-16 cultivars crosses 28 cultivar values gains 201911 201 11 2019-11 201918 18 2019-18 201910 10 2019-10 201916 16 2019-1 2 20191 20 1 2019-