Abstract. The study of plasma rotation in tokamaks is important for many reasons, for example, first, for creation of transport barriers, and second, for squeezing particle banana orbits in the core of large tokamaks. Recently, the first measurements of plasma rotation were performed in TCABR tokamak, which has the following parameters: minor radius a=18 cm, major radius R=61 cm, toroidal magnetic field B=1.1 T, discharge current I=100 kA, average density n = (1 - 3) . 1013cm- 3, T=200 eV, duration of the stationary phase of the discharge 60 ms. These preliminary measurements were fulfilled for a collisional plasma (Pfirsch-Schluter regime), using Doppler shift of carbon lines, measured using a high precision spectrometer. The radial profile of the poloidal velocity of a carbon impurity spectral line has been measured and the data analysis shows that U(max)=3.5 km/s. Presently, the uncertainty of the measurements is 1.5 km/s. Within the error limits, we can say that U is in good agreement with theoretical results for a collisional plasma. This first successful experiment on the study of plasma rotation in TCABR tokamak supports the continuation of this study, using an improved measuring system.