Background: In men with intermediate-risk prostate cancer (IR-PC) treated with low dose EBRT, the addition of androgen deprivation therapy (ADT) prolongs overall survival. Zumsteg proposes a subdivision for de IR-PC group: favorable or unfavorable. Purpose: retrospective evaluation of EBRT efficacy according to IR-PC subgroups (favorable or unfavorable). Methods: From the institutional radiotherapy department database, from 2000 to 2011, 95 men with IR-PC were identified and subdivided as follows: Favorable Risk (FR) – Gleason 3+4 or less and positive prostate biopsies (ppb) not exceeding 50% and only one intermediate-risk factor excluding 4+3; Unfavorable risk (UR) – Gleason 4+3 or at least 2 intermediate-risk factors or at least one intermediate risk factor and ppb >50%. Results: 95 patients were included in the analysis, mean FUP 6.2 years. 32.6% (31) had >50% ppb, 14.7% (14) had Gleason 4+3, 38.9% (37) had 2 intermediate-risk factors. 42.1% (40) were FR and 57.9% (55) were UR. Median EBRT dose: 79.8Gy. Only 25% of FR patients received some hormonal therapy treatment. There were no differences in time to Prostatic Specific Androgen (PSA) nadir (FR 12 vs UR 13 months; p= .50), biochemical relapse free survival (RFS) (FR 60 vs US 58 months; p= .80), or doubling time PSA (FR 12 vs UR 11 months; p= .19). Biochemical relapse (BR) and local relapse (LR) rates were lower for FR (BR: FR 27.5 vs UR 38.2%, p= .17; LR: FR 5 vs UR 14.5%, p= .40). Local RFS (FR 13.6 vs UR 9.6 years; p= .11) and distant RFS (FR 13.1 vs UR 12.4 years; p= .65) were longer for FR patients. Conclusions: Short course ADT is the standard treatment in IR-PC patients when EBRT is indicated, especially if they have UR features. In our study IR-PC group had heterogeneous outcomes and, in spite the study limitations, FR patients had a trend for better prognosis even with a very low use of ADT. If Favorable IR-PC patients may avoid ADT morbidity should be answered by a randomized trial.