Background: Besides noise, mechanical vibration of a general effect (whole body vibration), is an important physical risk factor that occurrs in the farmers' work environment. The vibration occurs on the seats of agricultural vehicles in motion, during the performance of specified field and transportation work tasks. Material and Method: The study covered the measurements of time schedules of agricultural activities, and effective values (RMS) for frequency of weighted vibration acceleration (equivalent), frequency corrected, on the seats of farm vehicles in three spatial directions of vibration (X,Y,Z) throughout the year. The basic vibration parameter was the dose (d). The following values were determined: total monthly vibration dose, mean equivalent daily vibration dose and mean equivalent daily vibration acceleration. Results: The highest values of the total monthly vibration dose occur both during summer-autumn months (August, September), and in spring (April, May). The mean equivalent daily vibration acceleration shows the highest values during four months of the year: April and May (0.50-0.53 m/s2), and August and September (0.47-0.50 m/s2); the average value of this parameter, for the whole year, reaches the level of 0.37 m/s2. Conclusions: Considering the fact that mechanical shocks occur in agricultural vehicles (mean maximum accelerations values registered: 0.86-0.99 m/s2; standard exceeding), and the threshold level of vibration exceeds the required values, adequate steps should be undertaken to protect private farmers against the risk resulting from exposure to mechanical vibration while performing their work. Med Pr 2010;61(2):143-154