BACKGROUND: Breast cancer is the most frequent type of cancer in women. The Nottingham Prognostic Index allows the use of a clinicopathological score, resulting in 3 prognostic groups. The aim of the present study was to determine the survival time and disease-free period and its association with the results of the application of the Nottingham Prognostic Index in patients with early stage breast cancer treated at Instituto De Cancerología y Hospital Dr. Bernardo Del Valle S, Guatemala. METHODS: An observational, descriptive, retrospective study was performed, which included 268 patients who underwent surgery after confirmed diagnosis of breast cancer, stages Ia, Ib, IIa or IIb according to TNM classification, between 2011 and 2014, at Instituto De Cancerología y Hospital Dr. Bernardo Del Valle S, of Guatemala. The study variables were: age, clinical stage, Nottingham index, molecular subtypes, survival and disease-free period, with a minimum follow-up of 5 years, until the last registered control. Chi-square calculation was used to look for correlation between the studied variables, statistical significance was considered with a p ≤ 0.05. RESULTS: The mean age of the patients was 56 years. The most common clinical stage was IIa (50%), among these patients 63% had a moderate prognosis (p ≤0.0001). The most frequent molecular subtype was luminal A (49%), of the patients with this subtype the majority (53% n=70) had a moderate prognosis (p=0.008). Among patients with a poor prognosis according to the Nottingham index, the majority (52.7%) had a disease-free period between 0 and 3 years and only 11% had a disease-free period of 7 or more years (p=0.043). Among those with a poor prognosis, the majority (47%) had a survival time between 0 and 3 years and 40.27% between 4 and 6 years (p=0.027). CONCLUSION: The results of the application of the Nottingham Prognostic Index have statistically significant association with clinical stage (p≤0.0001),molecularsubtype (p=0.008), disease-free period (p=0.043) and survival time (p=0.027); therefore it is a good predictor of survival time and disease-free period for breast cancer, and also allows us to correlate the different molecular subtypes and their prognosis.