To investigate the association of basal testosterone (T) levels with the outcome of in vitro fertilization (IVF) in women with diminished ovarian reserve (DOR). Complete clinical data on the first 223 IVF cycles in women with DOR were retrospectively analyzed. The associations of basal follicle stimulating hormone, luteinizing hormone, estradiol, and T levels with ovarian response and IVF outcome were studied. Basal T levels were significantly different between pregnant and non-pregnant women. However, basal T levels showed no correlation with controlled ovarian hyperstimulation parameters after adjusting for age. The association of basal T levels with pregnancy rate was significant after adjusting for other impact factors. Using receiver operating characteristic (ROC) analysis, the basal T level of 1.115 nmol/L for predicting pregnancy outcome had a sensitivity of 82.80 % and specificity of 58.09 %. The women were divided into two groups based on this value; although the clinical characteristics and ovarian stimulation parameters were similar, the clinical pregnancy (16.18 % (11/68) vs. 40.15 % (53/132), respectively, p = 0.000) and implantation rates (10.07 % (15/149) vs. 22.41 % (65/290), respectively, p = 0.002) were significantly different in the low and high T level groups. In women with DOR, the basal T level presented a positive association with pregnancy outcome in IVF. The poor reproductive outcome observed in women with lower basal T levels may be due to the decreased implantation rate.