[en] Optical parametric oscillators (OPO) provides tunable coherent radiation in a compact and efficient all-solid-state device. The recent progress in periodic poling of ferroelectric crystals enable new possibilities for realization of quasi-phase-matched OPOs. In this work we demonstrate continuous-wave OPO in periodically poled KTP (PP-KTP). Owing to its high effective nonlinear coefficient (∼ 9.5 pm/V), high photo refractive damage, low susceptibility to thermal lensing, the ability to operate near room temperature, as well as wide commercial availability of the KTP substrate, PPKTP is very attractive material for visible-pumped optical parametric oscillator. The poled crystal, which was polished and anti-reflection coated near the 532 nm (pump wavelength) and 1064 nm (OPO degeneracy wavelength), was placed inside a ring cavity. The device was pumped by a frequency-doubled CW Nd:YAG laser and parametric oscillations were observed above the threshold power of 55 mW. Up to 57So depletion of the pump was observed at a pump power of 78 mW. Wavelength tuning of the signal and the idler wavelengths was achieved by changing the PPKTP temperature or by changing the cavity length using a PZT in each temperature. The total tuning range was 1037nm - 1093 nm and was limited by the mirror coating. Tire total output power as 6.5 mW. By locking the OPO cavity length using an electronic servo and a PZT actuated mirror mount, we have obtained continuous output power from the device