The free-living mite species Sancassania rodionovi (Zachvatkin) (Acari: Acaridae), is a serious pest of mushrooms in Iran. Studies were conducted to examine the development of this mite in relation to temperature on two mushroom species: Agaricus bisporus Lange (button mushroom) and Pleurotus ostreatus Kummer (oyster mushroom). The developmental time of this acarid mite was studied at eight constant temperatures, ranging from 5 to 40°C, and developmental rates were modeled as a function of temperature. Sancassania rodionovi completed immature development in 17.35 ± 0.58 and 20.17 ± 0.88 d at 25°C on button and oyster mushrooms, respectively. When the mite fed on button mushroom, the rate of development increased gradually from 10 to 35°C. Using a linear model, the developmental zero was estimated to be 3.50°C with a thermal constant of 357.14 degree-days. The Logan 10, Briere 1, and Thermodynamic models adequately described the data for this mite and yielded R² values >0.95; these models provided estimates of optimum temperature for development of 33.244, 32.145, and 32.148°C, respectively. Understanding the influence of temperature on development of S. rodionovi is discussed with respect to pest management in mushroom production.