Diabetic mellitus patients are usually prone to chronic infections. However, there have been contradictory reports about the association between H. pylori infection and type II diabetes. The present study is aimed at evaluating the prevalence of Helicobacter pylori infection among type 2 dyspeptic diabetic patients in the littoral region of Cameroon. This cross sectional study comprised 93 type 2 diabetic dyspeptic patients and 112 non-diabetic dyspeptic patients attending the Gastroenterology Department at two reference hospitals in Douala-Cameroon. The study was approved by the local Ethical Committee of Medical Sciences. Participants were screened for the presence of both type 2 diabetes and H. pylori infection. Body mass index (BMI) of all the participants was also recorded. Data was analyzed using SSPS statistical package. H. pylori infection was found in 73.11% of diabetic patients versus 58.05% in non-diabetic participants, this difference was found to be significant (OR = 1.472, p = 0.0279). This relationship persists even when adjusted to factors such as age and income level of participants. Infected participants from age group ≥ 55 years and those with high income were those with a higher risk to develop diabetes. Infected patients with high BMI were more prone to develops diabetic mellitus compared with infected patients with normal BMI (p = 0.0034). Also, participant with high BMI were more prone to develops diabetic mellitus whether they were infected or not. Patients having both H. pylori + ve and BMI ≥ 25 kg/m2 were significantly more affected by diabetic mellitus than those in the others combined groups (p < 0.0001), suggested that high BMI and H. pylori infection together or not are factors that favor diabetes mellitus development. Separately or not, H. pylori infection and high BMI were risk factor for diabetes mellitus in our milieu.