Sweetness is an important attribute in the flavour, acceptability, and perceived quality of winter squash. Glucose, fructose and sucrose contributed differently to the perceived sweetness of eight winter squash cultivars (Cucurbita maxima) rated by a trained sensory panel. Sucrose was the most important sugar in predicting sweetness, but better predictions were obtained using additional combinations of glucose and fructose content. Sugar content and relative proportions of glucose, fructose and sucrose changed during storage. Starch content decreased for all cultivars during storage, and was an important predictor of sweetness for high starch cultivars only. When data for sweetness were regressed against sugar concentrations, adjusted R-2 Values in the range of 0.68-0.89 were obtained for seven of the cultivars. Including starch in the regression models unproved the adjusted R-2 values to 0.77-0.94. (C) 2000 Elsevier Science Ltd. All rights reserved.