Stage of cancer at diagnosis is one of the most important factors in patient prognosis. By controlling for diagnostic delay, this study aimed to identify factors associated with late-stage breast cancer (BC). From November 2014 to January 2017, required information on 497 patients who were newly diagnosed with BC was obtained from patients' medical records. Logistic regression was used to measure the association between cancer stage and study variables. Only 18.3% of patients were diagnosed at stage I. The rest were diagnosed at stage II (45.5%) or higher (36.2%). Among those with ≤ 3 months' diagnostic delay, age (odds ratio [OR] = 0.96; 95% confidence interval [CI], 0.93-0.99), place of residence (OR urban/rural = 1.72; 95% CI, 1.42-1.93), income (OR high/low = 0.27; 95% CI, 0.10-0.72), performing breast self-examination (OR yes/no = 0.51; 95% CI, 0.0.26 -0.98), smoking (OR yes/no = 2.23; 95% CI, 1.37-3.62), history of chest X-ray (OR yes/no = 1.40; 95% CI, 1.16-1.98), presence of chronic diseases (OR yes/no = 1.73; 95% CI, 1.36-5.48), and, for those with a delay of > 3 months, marriage age (OR = 0.83; 95% CI, 0.73-0.94), income (OR high/low = 0.07; 95% CI, 0.008-0.63), family history of BC (OR = 3.82; 95% CI, 1.05-5.05), daily exercise (OR < 10/10-20 = 0.10; 95% CI, 0.01-0.67), and presence of chronic diseases (OR yes/no = 1.77; 95% CI, 1.73-5.07), were associated with late-stage of cancer. Shortening the diagnostic delay can help patients receive medical treatment at an earlier disease stage, resulting in better prognosis. Smokers, younger women, and those with chronic conditions or a family history of BC should take extra caution, as they may have worse prognosis if diagnosed with cancer.