All international flights land at Rarotonga International Airport (RAR), about 3km west of Avarua. It is a small airport — there is no jetbridge, just stairs down to the tarmac — but it handles arrivals smoothly and the duty-free shop, currency exchange, and car rental desks are all there.
Air New Zealand operates the most frequent service, with daily flights from Auckland (about 3h 45m) and connections from Sydney, Los Angeles, and London. Hawaiian Airlines runs a weekly service from Honolulu. Jetstar operates several flights per week from Sydney. From Europe, the standard routing is via London to Los Angeles then onward via Honolulu or Auckland — expect a total journey of 24 hours or more.
One thing to be aware of: flights from New Zealand cross the International Date Line, which means you arrive in the Cook Islands the day before you departed Auckland. This confuses most people at least once.
No visa is required for stays up to 31 days for most nationalities. New Zealand passport holders get 90 days. You will need to show a return or onward ticket and proof of accommodation.
Inter-island flights are operated by Air Rarotonga, which serves most of the southern group islands and several in the north using small turboprop aircraft. Flights to Aitutaki take about 45 minutes; to the outer islands up to 4 hours. Day trips to Aitutaki by air are common and popular. Schedules depend on demand, so book ahead, especially in peak season.
By sea, cargo vessels run between Rarotonga and the outer islands, but schedules are irregular and passage is rarely practical for time-limited travellers. Cruise ships call at Rarotonga occasionally; the harbour is small and passengers are tendered ashore.