A walk-in type hemi cylindrical solar tunnel dryer has been built with heat protective north wall at College of Dairy and Food Science Technology, Udaipur, India for drying agricultural & horticulture product on large scale. In this paper attempt has been made to evaluate the performance of developed dryer to dry the seedless grapes (mutant Sonaka) The study show that chemically untreated grapes took seven days to dry at 16% (wb) moisture content The temperature gradient inside the tunnel dryer is about 10-28 degrees C during the clear clay, which is quite sufficient to dry agricultural commodities (C) 2010 Elsevier Ltd All rights reserved.