Abstract: A laser arrangement for generating narrow-band, tunable coherent radiation has an optical parametric oscillator (10) and a tunable seed oscillator (20) whose emitted seed radiation can be set in a narrow-band fashion by means of at least one wavelength-selective element (30). In order to achieve simple tunability of the output radiation (38) of the OPO in conjunction with a narrow bandwidth, good spatial beam quality and high beam intensity without maladjustment of the OPO resonator, the lineshape, set using the wavelength-selective element (30), of the seed radiation I.sub.seed (.lambda.), and the intensity transmission function T.sub.opo, (.lambda.) of the non-pumped resonator (12, 14) of the OPO (10) are set in such a way that given tuning of the center wavelength .lambda..sub.max seed of the seed oscillator (20) in the middle between two neighboring transmission maxima of the intensity transmission function T.sub.opo (.lambda.) it holds for all wavelengths .lambda. not equal to .lambda..sub.