Dissolution is one of the critical quality attributes for solid oral dosage forms, typically tablets and capsules. In addition as a quality control (QC) test to release commercial products, dissolution is often used as a comparative test to 1) apply biowaiver for lower strength(s) when multiple strengths of one product with the same or similar formulation are marketed, or 2) support post approval changes. In these cases, in-vitro dissolution test is used in place of in-vivo bioequivalence study to establish equivalency between products of different strengths or pre- and post-change. Guidances provided by major regulatory agencies, the United States Food & Drug Administration (US FDA) and European Medicines Evaluation Agency (EU EMEA) are often followed by many countries around the world. However some countries/ regions, such as Australia, Japan, China, Taiwan and Korea have their own country specific guidances. The dissolution requirements by the FDA and EMEA are generally similar, and depend on the type and level of changes as outlined in the relevant guidances. The requirements from other mentioned countries are often significantly different from that of US and EU, and different from each other. For products marketed globally, it’s prudent to understand the differences amongst the different country requirements when applying post approval changes using dissolution to demonstrate equivalency. Several sets of comparative dissolution studies may have to be conducted in order to satisfy all regulatory agencies. This presentation compares differences in dissolution testing requirements among the listed countries and provide examples to illustrate how for conduct studies to comply with the relevant guidance(s).