AbstractWorldwide, hazelnut (Corylus spp.) (Family Betulaceae) is one of the most economically important nut crops cultivated in the northern hemisphere. With its tasty nuts valued on the global market, emerging discovery of the plant pharmaceutical properties, and its role in sustainable agroecosystems, there is a quest to find and develop cultivars suitable for new growing areas. In a 2‐yr study, 53 hazelnut accessions from the Corvallis germplasm collection were evaluated for nut yield, kernel percentage, weight, and shape in the San Joaquin Valley (SJV) of California. The best traits were observed for ‘Lewis’ (PI 617210) and ‘Ennis’ (PI 557045); however, a few other accessions showed characteristics supporting cultivation in the SJV growing conditions. These findings might serve as a guidance for cultivar selection for farming in that region. The evaluation also contributed to the characterization of the USDA–ARS germplasm collection of Corylus.