Thin layer solar drying experiments of silkworm pupae using a solar tunnel dryer were conducted under the tropical weather conditions of Mahasarakham, Thailand. The dryer consisted of a transparent glass covered flat-plate collector and a drying tunnel connected in series to supply hot air directly into the drying tunnel using a blower. During the experiments, silkworm pupae were dried to the final moisture content of 0.15 kg water kg^-1 dry matter from 4.37 kg water kg^-1 dry matter in 373 min at the corresponding air flow rate of 0.32 kg s^-1. Ten different thin layer drying models were compared according to their coefficient of determination to estimate drying curves. The Midilli-Kucuk model precisely represents the solar tunnel drying behavior with the coefficient of determination (R²) of 0.9982. The maximum drying rate and effective moisture diffusivity were 0.6723 kg water kg^-1 dry matter h^-1 and 2.7696 × 10^-10 m² s^-1, respectively, on the drying air flow rate of 0.32 kg s^-1. A quality assessment shows that the lipid content of the dried silkworm pupae was not affected by the solar tunnel dryer. A slight decrease of polyunsaturated fatty acid (PUFA) was observed. © 2009 The Institution of Chemical Engineers.