Objectives: 1. Determine the incidence of cleft lip and/or palate defects in Cairo, Luxor, Aswan and New Valley governorates in the Arab Republic of Egypt. 2. Report gender and cleft type distribution in the four mentioned governorates. 3. Investigate etiological risk factors that may be associated with cleft lip and /or palate defects. 4. Compare the incidence of cleft defects, cleft types distribution and risk factors among the four governorates. Materials and methods: Before the initiation of the project, the Ministry of Health endorsed the maternity staff members which included the doctors and the nursing staff who will be participating in the program from every governorate to attend a one day course in the Faculty of oral and dental medicine – Cairo University. The course was conducted at the orthodontic department – Cairo University on how to detect, diagnose and classify the newly born cleft babies. The participants were trained how to fill in the diagnostic sheet and the diagrammatic sheet representing the classification of cleft lip/palate used in the study. At the end of that day, a small test was given to evaluate the ability of the staff to diagnose the cleft cases. Handouts and CDs were distributed for each participant to be as a resource or reference for any missing information. Diagnostic files containing ten diagnostic sheets and the diagrammatic representation of the classification of CL±P were provided for each medical unit, health care facility and main governmental hospital, each sheet having a sequential serial number for registering personal, familial, medical history and any predisposing factors for each newly born cleft baby. Data was monitored and collected monthly from all medical units and health care facilities in each governorate till the end of the year 2013. At the beginning of each month, the coordinator visited all the units to collect data of the affected live births of the previous month. A personal visit was performed to collect data and to keep in contact with the nurses and. These visits provided feedback about previously detected babies to stimulate interest and commitment from staff members. The incidence data was collected based on the number of births born in each city district in the governorate and calculated over the whole year. At the end of the year. Microsoft Office 2013 (Excel) and Statistical Package for Social Science (SPSS) version 20 was used. Results: The incidence of cleft lip and/or palate defects was found to be 0.47/1000 in Cairo governorate. The highest incidence of cleft lip and / or palate was found in Almoski district 14.56/1000 while the least incidence was 0.00/1000 in 15th May, Alkhlifa, Nasr Gharb, Altabeen, Boulak, New Cairo, Dar Alslam, New Masr, and RoudAlfarag health districts. The incidence of cleft lip and/or palate in Alzawia, Shubra, and Old Masr were 7.91, The incidence of cleft lip and/or palate was found to be 0.5/1000 in Luxor governorate. The highest incidence of cleft lip and/or palate was found in Luxor Center district having a incidence of 2.7/1000, while the least incidence was 0.00/1000 in Bandar Luxor, Alqarna, Alzainia, and Altawd health districts.The incidence of cleft lip and/or palate in Armant, and Asna were 0.9, and 0.5 /1000 respectively. The incidence of cleft lip and/or palate defects was found to be 0.12/1000 in Aswan governorate. However. The highest incidence of cleft lip and / or palate was found in Edfo Shark district having a incidence of, 0.22/1000 while the least incidence was 0.00/1000 in Draw and Nasr Alnouba health districts. The incidence of cleft lip and/or palate defects was found to be 0/1000 in New Valley governorate. A total incidence of 0.40/1000 of cleft defects was found in the four governorates. The highest incidence of cleft defects was found in Luxor governorate of 0.50/1000 while, the incidence of clefts in Cairo and Aswan were 0.47 and 0.12/1000 respectively. There was statistically significant difference in the incidence of cleft defects between the three governorates. Conclusion: 1. The mean incidence value of cleft lip and/or palate in the four Egyptian studied governorates was 0.40/1000.However, this incidence value varied significantly between 0.5/1000 in Luxor, 0.47/1000in Cairo, in Aswan0.12/1000, and 0/1000 in New Valley. 2. Cleft lip and/or palate defects were dominant in males than females in Cairo and Luxor governorates while females were dominant in Aswan governorate. However this sex differences were insignificant in all governorates. 3. The highest percentage of cleft type was cleft lip and palate followed by cleft lip and isolated cleft palate. Cleft lip and alveolus has the least percentage. Cleft type varied insignificantly between the studied governorates. 4. Unilateral cleft lip and/or palate represented higher percentage (100% - 72.7%) than bilateral clefts (0% - 27.3%) These differences were insignificant statistically. 5. Left sided clefts represented a higher percentage (67.5%-54.5%) than right sided in Cairo and Luxor governorates, however it was insignificant. On other hand, right sided clefts represented insignificantly higher percentage (100%) in Aswan governorates The highest etiological risk factor was maternal passive smoking in the four studied governorates followed by consanguineous marriage and medicine intake during pregnancy.