Optical disdrometers are present weather sensors with the ability of providing detailed information of precipitation such as rain intensity, kinetic energy or radar reflectivity, together with discrete information on the distribution of particle sizes and fall velocities (PSVD) of the hydrometeors. Disdrometers constitute a step forward towards a more complete characterisation of precipitation, being highly useful in several research fields and applications. In this article the performance of the two optical disdrometer most extensively used, the most recent version of Ott PARSIVEL<sup>2</sup> disdrometer and Thies Clima Laser Precipitation Monitor, is evaluated. During a two years precipitation observation experiment, four collocated optical disdrometers, two Thies Clima LPM and two Ott PARSIVEL<sup>2</sup>, recorded 58761 common one-minute precipitation observations, totalling 221 natural rainfall events, with intensities peaking at 220 mm h<sup>−1</sup>. The results show significant differences between both disdrometer types for all integrated precipitation parameters, which can be explained by differences in the raw particle size and velocity distribution (PSVD). Thies LPM recorded in average double number of particles than PARSIVEL<sup>2</sup>. PSVD percentile comparison showed Thies LPM measuring more small particles than Ott Parsivel<sup>2</sup>, resulting in higher rain rates and totals. These differences increased greatly with rainfall intensity. At rain rates above 10 mm h<sup>−1</sup> Thies LPM recorded nine times the number of particles of PARSIVEL<sup>2</sup>, affecting all precipitation variables. The practical consequences of these differences, and possible reasons, are discussed, in order to help researchers and users in the election of the sensor, pointing out at the same time limitations to be fixed in future versions.