Guilan Province is the biggest hazelnut producer in Iran. Over 70% of hazelnut production cost is due to its manual harvesting. Therefore, study on all aspects of its cultivation mechanization is necessary to sustain its production. This study focused on identifying factors that affect the development of hazelnut harvesting mechanization in Guilan Province, Iran, using a three-round Delphi technique. The technical panel of the study consisted of 27 hazelnut production in Eastern Guilan. The factor “observing engineering principles in the construction of new hazelnut orchards (row planting at appropriate density)” was identified as the most important driving factor with about 99% consensus from experts. Also, the factors “devising regional and provincial macro plans for developing orchard mechanization” and “development of mechanized irrigation of orchards with convenient methods tailored to local conditions” were ranked the second and third most important driving factors, respectively, with 91.30% and 90.05% consensus of experts. The most important inhibiting factor was found to be “the slope of most hazelnut farms” with 96% consensus of experts. The second most important inhibiting factors were “lack of appropriate roads for quick and convenient access to hazelnut cultivation machinery” and “hazelnut growers’ limited financial capability” with 94.75% consensus. These results indicated that it is necessary to address the modification of old gardens to oblige observing the construction principles of orchards tailored to hazelnut mechanical harvesting and to purposefully and specifically support research on the design and manufacture of small-scale implements for hazelnut harvesting tailored to local conditions of hazelnut orchards in Guilan Province. Manuscript profile