Technical Abstract: It was previously observed that a decrease in total soluble solids concentration in sugarcane (Saccharum sp. hybrids) juice was proportional to the magnitude of the change of temperature during the week prior to harvest (Eggleston and Vinyard, 1999. J. Am. Soc. Sugar Cane Technol. 19:62-63). I tested the hypothesis that a temperature change increased the activity of one or more sucrose cleavage enzymes in sugarcane internodes, resulting in a decrease in sucrose concentration. In a growth chamber, sugarcane was subjected to a 24-h treatment at 10°C before returning the chamber to a 10-h, 28°C day, 14-h, 18°C night regime. The transient temperature decrease slightly increased sucrose concentration in the most immature internodes sampled for the first two days after initiation of chilling. However, there was no significant change in extracted activities of the sucrose metabolism enzymes soluble acid invertase, neutral invertase, sucrose synthase, sucrose-phosphate synthase, and cell wall acid invertase. The slight increase in sucrose concentration was likely due to a suppression of endogenous activity of sucrose cleavage enzymes during the cold temperature. Thus, the cause of the effect of temperature changes on total soluble solids content in sugarcane juice is still not understood.