This study investigates the effects of coating with low molecular weight chitosan (LMWC, Mw = 15 kDa) and high molecular weight chitosan (HMWC, Mw = 357 kDa) on the decay of Murcott tangor and the maintenance of its quality. A 0.1% LMWC coating substantially slowed the decay of Murcott tangor stored at 15 °C in relation to a control sample and reduced decay by over 20% as compared to the fungicide TBZ. A concentration of 0.2% LMWC was more effective in controlling the growth of fungus on citrus fruits caused by Penicillium digitatum and Penicillium italicum, exhibiting effective antifungal activity. LMWC coating improved firmness, titratable acidity, ascorbic acidity and the water content for Murcott tangor stored at 15 °C for 56 days. Consequently, Murcott tangor coated with LMWC exhibited greater antifungal resistance than TBZ and its quality was maintained for longer.