Continuing professional development (CPD) is necessary for medical physicists to ensure that they are up to date with current clinical practice. Systems that monitor the CPD undertaken by medical physicists operate in 26 countries and are often used for certification, registration and license renewal purposes. They should be implemented in all countries where clinical medical physicists are employed. CPD is more than just continuing professional education (CPE). It can include research publication, working group contribution, thesis examination and many other activities. A survey of the CPD systems that are currently operated around the world shows that, in general, they are quite similar although are a few countries that have CPD systems that differ significantly from the others in many respects. Generally they ensure that medical physicists are kept up to date, although there are some that clearly will fail to achieve that. The different activities that are accepted as CPD were categorized. An analysis of what is required to construct a useful medical physics CPD system was made. The need for medical physicist professional organizations to cooperate and share in the production and distribution of CPD and CPE materials is explored. A higher level of international co-operation is recommended.