The impact of son preference on fertility in Egypt is analyzed using contraceptive practice as the end point. Data came from the 1980 Egyptian World Fertility Survey. The probability of contraception at each parity was estimated with a nonlinear maximum likelihood estimation of the cumulative logistic probability function. Dependent variables were number of sons at each parity duration of marriage wifes age at marriage husbands education religion wifes work and rural/urban location. Number of sons had a positive impact on contraceptive use at all parities. At low and high parity contraceptors had little son preference but contraception increased dramatically at each parity as the number of sons increased. The number of sons seemed to be the most important determinant of parity-specific probabilities of contraception. Education had a consistently positive and significant effect on contraception suggesting that economics motivated people to prefer well-educated quality children over quantity. Religion and wifes labor participation had no effect on probability of contraception. Sons are preferred in Egypt especially in rural areas because they cost less to raise contribute to family income with their higher earnings inherit agricultural land will potentially support parents in their old age and are preferred for social religious and status reasons.