The processing of tropical fruit juice has improved nowadays. Pitaya is one of the tropical fruits that have attracted the attention of consumers, fruit growers and also entrepreneurs in Malaysia. Since pitaya processing has just developed, more research should be conducted to increase the production quality of pitaya product such as fruit juice. In this research, pitaya juice production operations were studied from the peeling process to the production of clear pitaya juice using enzyme. Further research was done to develop a process flow sheet for the production of pitaya juice at laboratory-scale. Laboratory-scale processing was carried out to resemble the large-scale processing in the industry. Calculation of material balance was done based on the process flow sheet developed. Data obtained from this research can be used as a base for developing a large-scale pitaya juice production process at industrial level.