Background: Breast cancer tumours are the most common malignant tumours among women in Ethiopia. Although advanced-stage diagnosis of breast cancer is a common problem, evidence-based information is lacking about the magnitude and determinants of advanced-stage presentation in north-west Ethiopia.

Methods: An institution-based, cross-sectional study was conducted at the oncology units of the University of Gondar and Felege Hiwot specialised hospitals. Stages III and IV were considered advanced stage, whereas stages I and II were considered early stages. Data were collected prospectively on newly diagnosed breast cancer patients and entered using the EPI Info version 7.2 and analysed using Statistical Package for the Social Sciences version 23. Multivariable logistic regression was used to identify the determinants of advanced-stage diagnosis of breast cancer. A p-value < 0.05 was used as the cut-off point to select the determinants of the advanced stage.

Result: About 71.2% of breast cancer patients presented with advanced-stage disease. The median age of patients was 40 years. Rural residence (adjusted odds ratio (AOR) = 1.7; 95% confidence interval (CI): 1.02, 2.96), painless breast lump/wound (AOR = 2.5; 95% CI: 1.45, 4.13), travel distance ≥5 km (AOR = 3.2; 95% CI: 1.72, 5.29), not practising breast self-examination (BSE) (AOR = 2.9; 95% CI: 1.30, 6.52), time to presentation ≥3 months (AOR = 1.4; 95% CI: 1.02, 2.37) and misdiagnosed at first visit (AOR = 1.9; 95% CI: 1.09, 3.59) were determinants of advanced-stage breast cancer.

Conclusion: Nearly three-quarters of the patients were diagnosed with advanced-stage breast cancer. Not practising BSE, travel distance ≥5 km, rural residence, painless breast wound/lump and being misdiagnosed at first visit were important determinants of advanced-stage diagnosis of breast cancer. Focused awareness creation programmes for the public and increasing cancer diagnostic centres in the country are crucial to downstage breast cancer at presentation.