Pupil dilation has been widely linked to cognitive processes and is considered as a potential physiological marker of decision-making. However, it remains unclear whether pupil responses directly reflect learned stimulus values. Therefore, the present study investigated the relationship between pupil dilation, learned stimulus values, and subsequent choice behavior in a probabilistic decision-making task. Participants (N = 29) performed a reinforcement learning task in which they repeatedly viewed visual symbols associated with different reward probabilities and made choices based on trial-by-trial feedback. By presenting stimuli sequentially, the design allowed us to look at the relationship between pupil dilation and stimulus values directly. Behavioral results confirmed that the participants successfully learned the reward probabilities during the task. However, the results showed no relationship between pupil responses and stimulus values. There was a significant effect of pupil difference on choice observed, indicating that participants chose the stimulus with the greater pupil dilation. While the small effect size needs to be taken into account, the findings suggest that pupil response may act as a somatic marker in guiding decisions, but without encoding learned stimulus value. These findings contribute to the ongoing debate within the somatic marker hypothesis regarding the role of bodily signals in decision-making.