At the Hungarian Meteorological Service we receive the digital Meteosat images every 30 minutes and operate a radar network, which consists of two MRL-5 and one DWSR-25000 Doppler weather radar. The MRL-5 radar measures at 3 and 10 cm wavelengths in different ranges (32, 64, 128 and 256 km), while the Doppler radar at 5 cm in 480 km range. In this study we derive the cloud top heights (CTH) from Meteosat images and compare them with echo top values calculated from Range Height Indicator (RHI) vertical radar pictures. A cloud detection method has been developed using a threshold technique based on infrared and visible Meteosat data. The cloud top height is calculated operationally by using the infrared brightness values and ECMWF predicted temperature profiles. We got good agreement between the calculated cloud top heights and radar measurements for one-layer clouds, while bigger differences were obtained for cases, when clouds at different levels presented.