The development, reproduction, and population growth parameters of cotton aphid, Aphis gossypii Glover (Hemiptera: Aphididae), were studied on three different Cucumis sativus cultivars (Beith Alpha Balikesir, B.T. Bursaalpha, Beith Alpha MR,) under controlled conditions (25 +/- 1 degrees C, 65 +/- 5% RH, and a photoperiod of 16:8 (L:D) h. Life table parameters were estimated according to age-stage, two-sex life table method. Results indicated that the Bt Balikesir are favorable hosts for A. gossypii because of the shorter preadult developmental time, lower preadult mortality rate, and higher total fecundity on this cultivar. The intrinsic rate of increase (r = 0.4214 d(-1)), the net reproduction rate (R-0 = 51.80 offspring), and the finite rate of increase (lambda = 1.5242 d(-1)) values were higher on the Bt Balikesir. The effect of cucumber cultivars on the biology of A. gossypii was determined as significant and it was found that cv. Bt Balikesir was the most convenient cucumber cultivar in terms of the life cycle of A. gossypii. For an ecological and economic pest control, against aphids use of resistant or less favourable crop cultivars is considered one of the important components of integrated pest management. Therefore, results acquired might be used in pest management program that will be prepared for this aphid.