The main objective was to analyze the influence of social factors on the interval from diagnosis to treatment in a cohort of 217 patients with digestive tract cancer. From the clinical charts data were obtained for: date of the beginning of illness, dates of medical attendance, type and date of diagnostic tests, characteristics of the disease (symptoms, stage), and date of treatment. From the personal interview we gathered information lacking in the clinical charts such as socio-demographic factors, other underlying diseases, and variables related to life style. The information on hospital admission, diagnosis, and treatment was prospectively gathered, whereas data before hospitalization were retrospectively assessed. In statistical analysis the Kruskal-Wallis test and Cox regression were used. The predictors associated with a shorter diagnosis - treatment period were: low social class, lymphatic involvement at diagnosis, first visit at secondary/tertiary level of health care, no car availability, two or more symptoms at the beginning of disease, sex (male), age (less than 74 years), and diagnosis out of vacation periods. In conclusion, several socio-demographic variables (age, gender, social class, and car availability) influence the interval diagnosis - treatment.