Aim: To determine the effects of gender and seasonal variations on the prevalence of bacterial septicaemia among children 5 years and younger, and to identify the bacterial agents responsible for septicaemia and their antibiotic susceptibility profiles. Methods: Blood was collected from 1,724children (967 males and 757 females) aged 1 day to 5 years with clinical signs and symptoms of septicaemia. This study was carried out from 1 January to 31 December 2007 at the University of Benin Teaching Hospital, Benin City, Nigeria. The blood samples were processed to diagnosebacterial septicaemia. Bacterial isolates were identified and susceptibility test was performed using standard techniques. Results: An overall prevalence of 22.10% of confirmed bacterial septicaemia was observed in this study. Generally, gender and seasonal variations did not significantly affect the prevalence of bacterial septicaemia, though females (50.57%) during the dry season had significantly (p < 0.001) higher prevalence than their male counterparts (19.91%). Staphylococcus aureus was thepredominant bacterial isolate causing septicaemia in both seasons, while Citrobacter freundii was the least frequent. Pseudomonas aeruginosa was not recovered during the dry season. Most isolates were susceptible to gentamicin and cefuroxime, but only 1.44% of Staphylococcus aureus strains were susceptible to ceftriaxone. Conclusion: Bacterial septicaemia was observed in 22.1% of children 5 years and younger with clinical signs and symptoms of septicaemia. Seasonal variation did not affect the prevalence. Effect of gender was only noticed in the dry season, where females had a higher prevalence than males. Gentamicin and cefuroxime were the most active antibacterial agents. Rational use of antibiotics is advocated.Key words: Gender, Seasonal variation, Bacterial septicaemi