Soil-transmitted helminthiasis (STHs) are poverty-related diseases with high prevalence rates in developing countries. %e present study aims to describe the epidemiological scenario of STHs in an urban population in the Brazilian Amazon. A cross-sectional survey (n � 349 children aged 1–15 years) was carried out to obtain faecal samples and sociodemographic and sanitation data. Among the children, 143 (41%) were positive for at least one STH. Prevalence rates of infections by A. lumbricoides, T. trichiura, and hookworms were 24.4%, 42.6%, and 9%, respectively. A logistic regression multivariate model showed that infection with A. lumbricoides is significantly more frequent in children aged 11–15 years (odds ratio [OR] � 2.38; 95% confidence interval [CI] � 1.15–4.94; p � 0.018) and the presence of latrines inside houses is a protection factor against ascariasis (OR � 0.38; 95% CI � 0.17–0.85; p � 0.019). Positivity for T. trichiura is higher in the 5–10 (OR � 3.31; 95% IC � 1.85–5.89; p � 0.001) and 11–15 age groups (OR � 3.16; 95% IC � 1.66–6.00; p � 0.001), in children living in poor families (OR � 1.78; 95% IC� 1.01–3.14; p � 0.045) and practicing open evacuation (OR � 2.07; 95% IC � 1.07–3.99; p � 0.029). Hookworm infection is more frequent in children aged 11–15 years (OR � 6.70; 95% IC� 1.91–23.43; p � 0.002), males (OR � 6.35; 95% IC� 2.00–20.14; p � 0.002), and those living in stilt houses (OR � 3.52; 95% IC � 1.22–10.12; p � 0.019). %e use of albendazole in the last six months was a protection factor against hookworm infection (OR � 0.31; 95% IC � 0.10–0.96; p � 0.042). %e proportion of mild, moderate, and severe infections was 55.2%, 37.8%, and 7%, respectively, for A. lumbricoides, 72.4%, 24.3%, and 3.3% for T. trichiura, and 93.8%, 3.1%, and 3.1% for hookworms. Significantly higher worm burdens in T. trichiura and hookworm infections were associated with practicing open defecation and living in stilt houses. %e data points to the need to improve sanitation infrastructure in Amazonian cities with similar sociodemographic and environmental characteristics.