The study focused on economics assessment of garri processing in Rivers state, Nigeria. A purposive sampling procedure were used to select 120 respondents for this study. Primary source of data were collected with the use of structures questionnaire, and analyzed using mean, frequency and percentage, Gross Margin and Return on Investment. The findings revealed that 78.3% of the garri processors in Rivers State were female, while 21.7% are male. The average age of the garri processors were 45.5 years, with mean years in formal education of 9.9 years, and average years of experience in garri processing of 19.8 years. Furthermore, the results revealed that Gross Margin in processing 1338.84kg (the average processed cassava in the study area) of cassava roots into garri in Rivers State was N 10,561.60. While, the return on investment was N1.23, implying that for every one naira (₦1.00) invested in processing 1338.84kg of cassava roots into garri in the study area, a profit of ₦0.23k were realized, indicating 23% returns. Likewise, the results revealed that lack of funds, lack of improved garri processing equipment, health challenges, middlemen exploitation, lack of storage facilities, spoilage of cassava, and poor market linkages were the major constraints in garri processing business in Rivers State. Therefore, the study suggested that improved garri processing, and storage equipment developed by Nigerian Stored Products Research Institute (NSPRI) should be made available to garri processors in Rivers State by the government or NGOs in order to reduce waste in the system and increase returns. Also, adequate credit facilities should be made available to the garri processors in Rivers State.