Freshwater caltrop (Trapa acornis Nakano) fruits are very perishable and susceptible to browning, and thus have a short shelf life. In this study, minimally processed water caltrop (MPWC) fruits were treated with 0.0% (control), 0.5%, 1.0% and 2.0% of chitosan aqueous solutions, respectively, and stored at 4 ± 1 °C, 80–85% relative humidity for 15 day. Effects of the chitosan coating on MPWC fruit shelf life and qualitative attributes were evaluated by investigating fresh weight loss, browning index, phytochemicals and browning-related enzymes activities. Results showed that 1.0% and 2.0% chitosan coating significantly extended shelf life of MPWC fruit by reducing browning occurrence and fresh weight loss, preserving ascorbic acid, soluble solid and titratable acidity as well as total phenol content, also inhibiting the increase in phenylalanine ammonia lyase, polyphenol oxidase and peroxidase activities compared to the control during storage. However, 0.5% chitosan coating seemed to be ineffective in prolonging shelf life and conserving quality of MPWC fruit except for keeping more total phenols during storage in comparison with the control.