The aim of this research was to investigate the environmental impacts of olive fruit production under different orchard size and upon organic and common agro-systems through Life Cycle Assessment (LCA) methodology in Rudbar region, Guilan province, northern Iran. The data were collected using a self-structured questionnaire and face-to-face interview with 305 olive growers in the study region. Six environmental impact categories including depletion of fossil fuels, global warming, acidification, terrestrial eutrophication, depletion of phosphate and potash resources have been investigated in the research. One ton of olive fruit was set as the functional unit (FU). Results showed that the large olive orchards (≥5ha) had the widest impacts in all environmental categories. Overall, acidification, terrestrial eutrophication, and depletion of phosphate resources have been identified as the most important environmental challenges of olive fruit production with final indices of 1.58, 2.68, and 3.12, respectively. Organic olive orchards had better environmental performance than the common ones in all impact categories particularly in cases of acidification, terrestrial eutrophication, and depletion of phosphate and potash resources with a nil amounts. Therefore, substituting a great portion of chemical fertilizers used in the large olive orchards with the biological alternatives such as farmyard manure have been suggested to provide the nutritional requirements of olive trees. So, a regional strategy should be planed to move to an appropriate integrated farming system to cut down the environmental hazards of olive fruit production in large orchards in Rubar region, northern Iran.