The paper presents the structure of a synthetic indicator created to measure the level of influence of agricultural farms on the natural environment. The author describes both the set of parameters used for the purpose of creating the indicator as well as the specific character of these parameters and the measurement method. The described methodology has been used in the analysis of agricultural firms formed on the basis of property formerly belonging to the State Treasury. Two planes of the operation of the analysed entities have been considered, namely the financial and environmental ones. Changes in both the selected financial indicators and environmental effectiveness, treated as the resultant of fluctuations in the diagnostic features, have been analysed. The dependence linking the examined phenomena has been determined and conclusions relating to the investigated group of entities have been formulated.