A pleated filter cartridge is a potential component to reduce the installation space required for a bag house dust collection system. However, the optimal pleating method has not been suggested yet, and it has been dependent upon the manufacturer's know-how and experience. In this study, dimensionless parameter, alpha, which is the ratio of pleat height to pleat width, was introduced to determine the optimal pleat geometry of a pleated filter cartridge. Eight different pleated filters were prepared to determine the effect of alpha and pleat length, P-L, on the filter cleaning efficiency. A lab-scale pulse jet bag house system which could install four filter bags and to be capable of on-line filter cleaning, was used to perform the filtration tests. Based on experimental data, a pleated cartridge filter with alpha = 2.21 had the maximum effective filtration area, and filter cleaning efficiency. However, we observed a drastic decrease in filter cleaning efficiency for a filter with an alpha value higher than 2.21. Therefore, we found that the tested cartridge filter had the optimal filter pleating geometry at alpha = 2.21, which folds a filter medium as a ratio of pleat height to pleat width, 2.21. In addition, the effective filtration area of a pleated filter cartridge was measured by the relationship between the increase in pressure drop during each filtration cycle, and multiplication of dust concentration and elapsed time. The ratio of the effective filtration area and theoretical filtration area, beta, depends on the filtration cycle and the alpha value at the initial stage; however, it only depends on the a value at a later stage. (C) 2018 Elsevier B.V. All rights reserved.