Summary Objective To determine the prevalence and identify intra-familial risk factors associated with Helicobacter pylori infection in a paediatric population. Methods Cross-sectional study in the Buea and Limbe health districts, South West Cameroon. Stool samples were collected from 176 randomly selected apparently healthy children from two communities with different socioeconomic status. They comprised 86 males and 90 females aged 0–10 years with a mean age of 4.29. Helicobacter pylori status was determined using an enzyme-linked immunosorbent assay, the H. pylori stool antigen (HpSA) test. The test uses polyclonal anti-H. pylori capture antibody to detect H. pylori antigens in human stool. Epidemiological data were analysed using the Fisher test and odds ratio (OR) at 95% confidence intervals (CI). Results The overall prevalence of H. pylori was 52.27% (92 of 176). Univariate analysis showed that H. pylori prevalence was significantly higher in children of the low socioeconomic class, 62.50% (55 of 88) than in those of the high socioeconomic class, 42.05% (37 of 88) (P < 0.05; OR = 2.41, 95% CI: 1.26–4.64). Helicobacter pylori prevalence increased with age from 37.50% (12 of 32) for children aged <3 years, 50.00% (53 of 106) aged 3–6 years and 71.05% (27 of 38) aged 7–10 years (P > 0.05; OR = 0.81, 95% CI: 0.34–1.91). The frequency of infection was significantly higher in males, 64.00% (55 of 86) than in females, 41.11% (37 of 90), (P < 0.05; OR = 2.67, 95% CI: 1.39–5.17). Conclusions This study highlights the continuing importance of age, sex and socioeconomic status in the acquisition of H. pylori infection.