Potassium channels (KCh) in corpus cavernosum play an important role in the regulation of erection. Nitric oxide (NO) acts through opening of KCh leading to hyperpolarization and relaxation. This study aims to update knowledge about the role of voltage-gated KCh (K) channels in erectile machinery and investigate their role in the control of NO action &/or synthesis in the corpus cavernosum. Tension studies using isolated rabbit corpus cavernosum (CC) strips and rat anococcygeus muscle were conducted. Results are expressed as mean ± SEM. Electric field stimulation (EFS, 2-16 Hz) evoked frequency-dependent relaxations of the PE (phenylephrine)-precontracted CC strips. At 2 Hz, EFS-induced relaxation amounted to 73.17 ± 2.55% in presence 4-AP (10 M) compared to 41.98 ± 1.45% as control. None of the other selective KCh blockers tested inhibited EFS-induced relaxation. 4-AP (10M) significantly attenuated ACh-induced relaxation of rabbit CC where dose-response curve was clearly shifted upward, and attenuated SNP- induced relaxation, for example, to 49.28 ± 4.52% compared to 65.53 ± 3.01% as control at 10 M SNP. The potentiatory effect of 4-AP on EFS was abolished or reversed in presence of N -nitro-L-arginine (L-NNA, non-selective nitric oxide synthase inhibitor, 10M, and 2 × 10M). Same results were observed in rat anococcygeus muscle which is a part of the erectile machinery in rats. This study provides evidence for the presence of prejunctional voltage-gated KCh in CC, the blockade of which may increase the neuronal synthesis of NO.