In Plasco, Inc. v. Thantri Meethikulchanun, the Dika Court considered the IP&IT Court’s dismissal of the plaintiff’s complaint, which had been based on the reasoning that the complaint was filed after the expiration of the five-year period for filing a cancellation action based on “better right” grounds under Section 67 of the Thai Trademark Act. The Dika Court reversed the IP&IT Court’s decision on how the period was to be calculated. In addition, it insisted that when a claim is based on passing-off grounds, the claimant’s mark shall be required to have a reputation as a well-known mark. This article summarizes the decision.