EU nationals, in general, do not require a visa, however most other non-German participants do.

Please follow the link to check that you do in fact need a visa: German Federal Foreign Office
Those who need a visa must satisfy the visa requirements of their local German Embassy/Consulate including

1. a visa invitation letter
2. a  confirmed travel booking, including a flight, train and/or bus booking, hotel reservation and health insurance
3. a confirmed order for their online registration as well as any special local requirements.

Therefore, all intended visitors should first register on-line for their entrance ticket. Online registration offers several cost and time saving benefits as described at the following link tickets and registration.
 
Those who need a visa should then request a visa invitation letter, which is available at the following link visa invitation letter and take it along with all travel documents to the German Mission (Embassy or Consulate) responsible for their present place of residence to apply for a visa.

For frequently asked questions pertaining to visa applications please click here.

For further questions with regard to visa matters, please consult Messe München’s subsidiary in your country or contact Ms Ursula DORNA visaservice@messe-muenchen.de.