In this study we determined the short-term effects of a glucose drink and a sucrose drink compared to a placebo on cognitive performance and mood in elderly people with subjective, mild memory complaints using a randomized crossover study design. In total, 43 nondiabetic older adults with self-reported memory complaints were included. Drinks consisted of 250 ml with dissolved glucose (50 g), sucrose (100 g), or a mixture of artificial sweeteners (placebo). Multiple neuropsychological tests were performed and were combined by means of z scores into four cognitive domains: episodic memory, working memory, attention and information (processing speed), and executive functioning. Mood was assessed with the short Profile of Mood Status (s-POMS) questionnaire. Blood glucose concentrations were measured at five time points to divide participants into those with a better or poorer blood glucose recovery. Performance on the domain of attention and information processing speed was significantly better after consuming the sucrose drink (domain score of 0.06, SD = 0.91) than after the placebo drink (–0.08, SD = 0.92, p = .04). Sucrose had no effect on the other three domains, and glucose had no effect on any of the domains compared to the placebo. When dividing participants into poorer or better glucose recoverers, the beneficial effect of sucrose on attention and information processing speed was only seen in participants with a poorer recovery. After sucrose consumption, depressive feelings and tension were slightly higher than after the placebo. To conclude, 100 g sucrose, but not 50 g glucose, optimized attention and information processing speed in the short term in this study in elderly people with subjective, mild memory complaints.