The aim of this study into evaluate the treatment results of three dimensional conformal radiotherapy (3DCRT) and androgen deprivation therapy (ADT) in patients with clinically localized prostate cancer (CLPC). Between June 1998 and December 2011, 577 patients with the diagnosis of CLPC were treated. ADT was started 3 months prior to radiotherapy (RT). 3DCRT was delivered to prostate and the seminal vesicles (SV) to a total dose of 70Gy. Additionally, patients with lymph node (LN) positivity received 50.4Gy RT to pelvic LN's. Median follow up time was 65 months. Five-ten years overall survival (OS), cause specific survival (CSS), PSA relapse-free survival (PSA-RFS) and distant metastasis-free survival (DMFS) rates were 92-74%, 97-91%, 77-55% and 94-88%, respectively. OS was negatively affected from LN positivity (p < 0.001). In the subgroup of patients With GS 8, there was no significant difference between < 1 years and 1 years of ADT in terms of CSS, PSA-RFS and DMFS. OS was better in patients with < 1 years of ADT (p = 0.01). Five year OS (p = 0.02), CSS (p = 0.05), PSA-RFS (p = 0.01) and DMFS (p = 0.07) rates were inferior in the high risk group patients that used ADT 1 year. Acute and late RTOG grade III/IV gastrointestinal system toxicity rates were 1.7% and 5% and acute and chronic RTOG grade III/IV genitourinary system toxicity rates were 1.4% and 5%, respectively. 3DCRT and ADT combination is an effective treatment modality with acceptable toxicities in patients with clinically localized prostate cancer.