Interest in sex selection has a long history dating to ancient cultures. Methods have varied from special modes and timing of coitus to the practice of infanticide. From a total of 40 case started, we achieved 28 clinical pregnancies of which 2 cases were aborted, and 5 cases were delivered and have had 6 male live births with no congenital anomalies so far with ongoing 21 pregnancies. 4D U/S was done for 12 cases and revealed twin male embryos for 4 cases and single male embryo for 8 cases with no congenital anomalies which confirm that PGD is a safe and accurate technique for sex selection. In this study we also studied the effect of modified swim up technique on sex of embryos when we used this technique for processing the semen sample of 18 males. We found that this technique when applied the number of male embryos increase by more than 50% of the total embryos. In this study we also studied the effect of cigarette smoking on male: female birth ratio and we found that smokers were having more girls than non smokers.