We examined the impact of induced goal orientation on individuals' positive‐ and negative‐activating mood when taking part in high‐ or low‐challenging assignments. Results indicated that performing a low‐challenging assignment leads to a higher positive‐activating mood with a performance‐approach orientation than with a mastery approach, or no goal orientation. In contrast, conducting a high‐challenging assignment leads to a higher positive‐activating mood with a mastery approach than with a performance approach, or no goal orientation. These findings suggest that high‐challenging assignments are best instructed with a focus on learning whereas low‐challenging assignments are best instructed with a focus on superior performance.