Tempeh is one of Indonesian traditional fermented food that is made through fermentation of cooked soybean or other ingredients by the role of Rhyzopus sp. Tempeh is widely known as it possesses wide nutritional benefits, such as high protein, fiber, and antioxidant activity. Development of tempeh flour was found to be able to prolong its shelf life and increase product innovation of tempeh. Tempeh flour can be applicable as a substituting ingredient in wheat flour based products, such as bread. This research was aimed to determine the best tempeh flour to wheat flour ratio and particle size of tempeh flour that can produce an acceptable bread. Six different tempeh flour to wheat flour ratio (5:95, 10:90, 15:85, 20:80, 25:75, 30:70) and three different particle sizes (fine particles (<250 μm), semi-coarse particles (250-500 μm), coarse particles (500- 1000 μm)) were applied as the treatments. The physicochemical including height of loaf, specific volume of loaf, lightness of crust, whiteness degree of crumb, and firmness of crumb, as well as sensory properties of the final bread product were assessed. The result showed that the higher addition of tempeh flour resulted in lower bread loaf height and specific volume, along with darker crumb color and firmer crumb texture, which was less accepted by panelists. Bread made with 10:90 tempeh flour to wheat flour ratio in coarse (500-1000 μm) particle size was chosen as the best bread formula. It possessed higher protein (10.3867%) and antioxidant activity (33.184mg AAE/100g dry sample) compared to control bread and classifies as “high source of fiber” by containing 7.36% of total dietary fiber.