Despite the important frequency of the gene "S" in Togo, essential information remains insufficient to elaborate a prevention campaign on this affection. In order to assess the knowledge on sickle cell diseases as well as the prevention practices in the Togo population in one of the five districts of the township of Lomé, a cross sectional study was conducted in the third district of the township of Lomé from January 21, 2004 to January 26, 2004 in 210 natives from Togo aged of 15 and over, through a semi-structured questionnaire. The variables studied were: - the socio-demographic features and the knowledge of sickle cell disease characteristics (symptoms, biological diagnosis, treatment and means). Data collected were analysed through software Statically Package for Social Science (SPSS) version 10.0 of Windows using the chi2 test with 5% significance in the comparison of some variables. 117 women and 93 men were interviewed. Sickle cell disease was known in almost all ethnic groups but incompletely: 79.5% of the individuals knew about premarital check up but only 12.4% knew about haemoglobin electrophoresis check up. 74,8% of the people had a good knowledge of the cause of sickle cell disease, 78.6% had a fairly good knowledge of its symptoms, 57.6% knew the factors inducing attacks, 64.3% the prognosis and 69.5% the prevention methods, but a poor knowledge of the complications (62.4%), biological diagnosis (71%) and treatment (97.2%). The prevention practices were poorly adopted: 12% had an haemoglobin electrophoresis check up and 15% of them had their husband to have one as well. Professional status influenced the level of knowledge of the biological diagnosis (p=0.001) and prevention means (p=0.018). The educational level influenced biological diagnosis knowledge (p = 0.000) and prevention means (p = 0.02). On the whole, sickle disease was linked to marital status (p = 0.00). Sickle cell disease remains quite unknown in spite of the gene "S" important frequency in Togo. These results are to be taken into account to implement information, education and communication program to struggle against sickle cell disease.