Several studies have established an association between the blood group type and susceptibility to infections. This study aimed to evaluate a correlation between the blood group type and the susceptibility to infection. 558 patients were enrolled in this study who attended at the Althawra Hospital, Ibb city, from March to August 2018. A blood sample was analyzed for complete blood count (CBC) and blood group. High frequency of infections affecting the digestive system (26.4%), while the less affected system is the urogenital system 5.9%. Patients with A blood group have increased probability to be infected by viruses than bacteria(Odds Ratio =1.430; 95% Confidence Interval =1.005 to 2.035; p= 0.05) and (OR=0.098; 95% CI=0.064 to 0.148; p<0.0001) respectively It was observed that blood group A persons were more liable to infection with hepatitis B virus than other groups (p=0.041; OR=1.704, 95% CI=1.053-2.773). The liability of O blood group patients for urogenital infections was less than non-O blood group patients by third (OR=0.353, 95% CI=0.158-0.789; p0.014). This study corroborates previous findings that showed that certain blood groups are more prone to infection by one agent than patients with other blood groups.