This study focuses on the effects of process parameters of rotary tablet press on die filling behavior during the mini-tablet production. Fill cam type, adjusted fill depth, and disc rotational speed were modulated, and mean tablet weight, mean powder fill level, and relative standard deviations for tablet weights were evaluated. To examine the differences between the production processes of mini-tablets and conventional tablets, typical-sized tablets were studied as a reference. When producing conventional tablets, excessively deep fill cam and high disc rotational speed negatively affected die filling efficiency and weight variation. In contrast, for mini-tablets, deep fill cam and high disc rotational speed were suitable for efficient and reproducible die fill. These were closely related to the die retention time under powder bed and the degree of powder suction. Since die filling for mini-tablet production was significantly different from conventional tablet, understanding its characteristics is necessary to ensure tablet quality. (C) 2019 Elsevier B.V. All rights reserved.