A rapid population growth is a burden on the resources of many developing countries. Unregulated fertility, which contributes to such situations, compromises the economic development and political stability of these countries. Contraceptive use is the lowest in Yemen where about 1 out of 5 married women of reproductive age use contraception and only about 1 out of 10 married women use a modern method. The study conducted to evaluate the impact of implementing an educational program of family planning upon Yemeni women at Sana'a City. The study was Quasi-experimental research design. It was conducted in Al-Sabeen Hospital and Al-Olofi Center for Childhood and Motherhood which included a sample of one hundred and forty women, divided equally into two groups: study group and control group (seventy for each group). It included three tools; tool one a social demographic data and women’ knowledge about family planning. Tool two women’ attitude toward birth control. Tool three educational program about family planning. More than half of the control group (57.1%) whose age was between 30 years and less than 40 years and (40%) of studied group and (45.7 %) of the control group had preparatory education. The number of pregnancies was more than two fifth (41.4%) of the study group had three or more times while (58.6%) about two third for the control group. Unwanted pregnancy represented (64.3% and 57.1% respectively) of both study and control group. Women' knowledge had a poor score on pretest, improved to good score on immediate post test, and remaining good score with slight decrease on follow up test. Their attitudes score were slight positive attitudes on pretest, but increased on immediate post test, and on follow up test. There was highly statistically significant difference between the women’ knowledge about FP in pre, immediate post test and follow-up. Also, there was a highly statistically significant difference between women’ attitude in pre and immediate post test and follow-up test. Family planning program should involve men as well as women, design and implement a strategy to ensure all primary health care clinics provide counseling on FP.