The aim of this study 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 northern Iran. The data were collected using a self-made questionnaire and face-to-face interview with 305 olive growers in the study region. Six environmental impact categories (IC) including depletion of fossil fuels, global warming, acidification, terrestrial eutrophication, depletion of phosphate and potash resources have been investigated. One tone of olive fruit was set as the functional unit (FU). Results showed that the large olive orchards (≥5ha) had the highest negative environmental impacts in all studied IC. 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. The results also revealed that the organic olive orchards are more environmental efficient than those of conventional orchards. Substituting a certain portion of chemical fertilizers used in the large olive orchards with the biological alternatives such as farmyard manure has been suggested to provide the nutritional requirements of olive trees. A regional strategy should be also planned to move to an appropriate integrated farming system to cut down the environmental hazards of olive fruit production in large orchards in the studied region. Manuscript profile