In recent years, eco-friendly practices have gained importance in agricultural production. Therefore, the aims of the study were to estimate the efficiency measures of participant and non-participant to the Environmentally Friendly Agricultural Land Protection Program (EFALP) in Samsun province of Turkey, to determine the effects of participating the program on the farm level production efficiency and to calculate the opportunity cost of conversion to eco-friendly farming system in Samsun provinces of Turkey. The bulk of the data were collected from randomly selected 133 farms and cluster analysis was performed to select similar farms. Data Envelopment Analysis (DEA) was used to estimate efficiency scores. Opportunity cost of conversion was calculated by comparing the net revenue of eco-friendly farming system and conventional one. Research results showed that the mean technical, allocative and cost efficiencies of participant farms were lower than non-participant ones. The opportunity cost of conversion eco-friendly farming and environmental subsidies paid by government were (sic)468,98 and (sic)500,87 per hectare, respectively, indicated that subsidies met the loss sourced from conversion in the research area. It was clear based on research findings that farmers would increase their technical competence, if they improved their skills via participating training and extension programs. Since the opportunity cost of the conversion was the main drivers of farmers' satisfaction from eco-friendly farming system, increasing the number of participants and continuing this support policy for environmental protection considering the balance between loss and subsidy may increase the succeed to protect of human health, soil and water resource protection.