Five experiments explored the methodology of Web-based mood induction and yielded empirical evidence for its feasibility and its limits. Study 1 examined the suitability of the Velten method and mood-suggestive photographs to induce both positive and negative moods. Negative mood was successfully induced, while the positive mood induction failed. In Study 2, cartoons successfully ameliorated mood, whereas jokes were ineffective. In Study 3, associations with affectively valenced words were not suitable in producing a positive or a negative mood. In Study 4, picture-illustrated emotive texts successfully induced a positive and a negative mood. In Study 5, valence and arousal ratings were obtained for the stimuli used in Study 1 and 3. Based on the results, recommendations for the application of online mood induction procedures are given.