Drawing on the mood-behaviour model (Gendolla, 2000), two studies investigated informational effects of mood on effort-related cardiovascular response. Experiment 1 manipulated mood state (positive, negative) and task difficulty (easy, difficult, extremely difficult). Effects on cardiovascular reactivity were as expected: On the easy level, reactivity was weak in a positive mood, but strong in a negative mood; on the difficult level, reactivity was strong in a positive mood, but weak in a negative mood; on the extremely difficulty level mood had no (...) effect. Experiment 2 manipulated mood only. As predicted, subjective demand and cardiovascular response were both higher in a negative mood than in a positive mood and the mood effect on cardiovascular response diminished after statistically controlling for the demand appraisals. Neither study revealed any mood effects on cardiovascular response during the mood inductions. (shrink)