INTRODUCTION: Radical prostatectomy is considered as a curative treatment option in clinically localised prostate cancer patients. Therapy failure is related to positive surgical margins and/or extracapsular extension. The use of neoadjuvant combined androgen blockade (CAB) withdrawal therapy, mainly in cT2 disease, has been shown to decrease positive margin rates. However, CAB therapy remains controversial since there is no proof that this approach confers any benefit in relation to biochemical and clinical disease-free survival. Increasing negatives surgical margins and lower tumour volume (TV) with prolonged CAB therapy has been recently reported. AIM: To analyse the effect of 6 months neoadjuvant CAB therapy in front of 3 months in clinically localised prostate cancer patients submitted to radical prostatectomy. PATIENTS AND METHODS: The pathological stage and TV in forty-two patients treated by 6 months in front of thirty-four patients treated by 3 months were studied. The relationship of clinical stage and initial PSA concentration were analysed. RESULTS: TV was significantly lower in 6 months treated patients (0.97 cc vs. 0.48 cc, p = 0.05). The lowest TV was observed in cT1 patients, but significant differences only were observed in cT2 (1.5 cc vs. 0.86 cc, p = 0.04). No relationship between TV and PSA was obtained. No differences in the incidence of organ-confined disease were seen depending of the CAB length (47% vs. 43%, p = NS). However, increasing incidence of specimen-confined disease was observed in 6 months treated patients (56% vs. 74%, p = 0.05). CONCLUSION: The duration of neoadjuvant CAB can affect both TV and surgical margin status. Lower TV and increasing incidence of specimen-confined disease with 6 months CAB treatment were observed. Patients with palpable disease may be more benefited by this treatment option.