PIP: The sex ratio in the Kuwaiti population has declined from 109.1 in 1961 to 98.5 in 1985. 5 factors which influenced this change in sex ratio in the Kuwaiti population are 1) sex differentials in errors in census counts, 2) migration, 3) sex ratio at birth, 4) sex differentials in mortality, or 5) mixed marriages. Results show that only the mortality differential between Kuwaiti males and females and the mixed marriages of Kuwaitis with non-Kuwaitis contributed to the 70% decline in sex ratio during the period 1975-1980. The impact of errors in census counts on sex ratio could not be precisely estimated in the absence of post enumeration surveys. The influence of birth order and maternal age on sex ratio was also studied through regression analysis and by linear and quadratic models; results suggest a nonlinear relationship. No trend in sex ratio at birth was found by the author, and study of Kuwaiti migration shows it to be irrelevant for Kuwaiti nationals.