To describe delay intervals, their impact on clinical stage and initiation of first oncologic treatment, and evaluate associated factors in breast cancer patients in Yucatan, Mexico, a low-density population region. A retrospective analysis was done of 92 medical records, and bivariate and multivariate models applied to identify associations between healthcare delay and several factors. System delay accounted for most of the delay (median: 86 days; 61% of delay). Socioeconomic status and delivery to tertiary-care hospital predicted delay. Clinical stage determined initiation of first oncologic treatment. Delay in treatment was largely due to system delay. Only a few variables explained this delay. Clinical stage had the strongest effect on initiation of first oncologic treatment.