Visas are not required for stays up to 31 days on the Cook Islands. Beyond that, you will need to apply for a visa at the Immigration Department which can be extended for up to five months on a monthly basis, though applications must be made no later than two weeks before the expiration. A valid passport along with a return ticket or a proof of onward travel is required to enter the Cook Islands.
Health and Safety
Vaccinations against tuberculosis are sometimes advised, but otherwise there are few health risks to worry about on the Cook Islands. There are occasional dengue fever outbreaks, but most times of the year mosquitoes are nothing, but a nuisance. Wearing bug spray is a good idea nonetheless. Water is untreated so if you are particularly sensitive, do not drink from the tap, as bottled water is widely available. Hospitals are located on the main island of Rarotonga and Aitutaki, and there are private medical clinics on other islands. Having a comprehensive travel insurance plan is recommended when going anywhere.
Crime is virtually nonexistent, and it is very safe to roam around the towns even after dark. However, be careful when driving motorcycles, as accidents are the main cause of injuries and even fatalities. Driving after dark is especially risky because of poor visibility.