Purpose of the study. To investigate the sociodemographic and clinical characteristics of complicated intra-abdominal infections in patients admitted to a surgical hospital in a northern industrial region of Russia, with special emphasis on labor migrant status and timing of hospitalization. Material and methods. A single-center prospective descriptive study included 75 adult patients hospitalized with complicated intra-abdominal infections requiring surgical treatment. The study was conducted at the surgical department of Lyantor City Hospital. Eligible patients were older than 18 years and had peritonitis or intra-abdominal abscess with at least one positive intraoperative bacteriological culture obtained from the infectious focus. The analysis included sex, age, migration status, clinical form of infection, underlying nosological structure, and timing of hospital admission. Statistical processing included descriptive statistics and comparative analysis of categorical data using Pearson's chi-square test. Quantitative variables are presented as mean ± standard deviation. Differences were considered statistically significant at p < 0.05. Results. The mean age of the patients was 48.1 ± 5.3 years. Men predominated and accounted for 68.0% of the cohort. Labor migrants working on a rotational basis constituted the majority of the study population, 68.0%, whereas local residents accounted for 32.0%. Peritonitis was the dominant clinical form and was diagnosed in 82.7% of patients, while intra-abdominal abscess was identified in 17.3%. The leading causes of complicated intra-abdominal infections were acute destructive appendicitis, 33.3%, acute destructive pancreatitis, 28.0%, and perforated gastric or duodenal ulcer, 17.3%. Delayed hospitalization, defined as admission more than 24 hours after symptom onset, was observed in 60.0% of patients. Among labor migrants, delayed hospitalization occurred significantly more often than among local residents, 68.6% versus 41.7%, respectively (χ² = 4.94; p = 0.026). Conclusion. In a northern industrial region, labor migrants working on a rotational basis represent a high-risk group for delayed access to medical care in the setting of complicated intra-abdominal infections. These findings highlight the need to improve patient routing, early detection of urgent surgical pathology, and locally adapted protocols for high-risk migrant populations.