Sumbawa is reached from Lombok by ferry or by air. The main ferry crossing is between Lombok's Kayangan port and Sumbawa's Poto Tano harbour at the western tip of the island — the crossing takes about two hours and boats run frequently through the day. From Poto Tano, it is another 2–3 hours by road to Sumbawa Besar, the main town.
Sumbawa Besar has a small airport (Sultan Muhammad Kaharuddin III Airport) with flights from Lombok, Bali, and occasionally other Indonesian cities. Check current schedules as these vary by season and carrier.
At the eastern end of the island, Bima has its own airport (Sultan M. Salahuddin Airport) with connections to Lombok, Bali, and Makassar — useful if you are approaching from or heading to Sulawesi.
By road, Sumbawa sits on the Trans-Nusa Tenggara route: buses travel the full length of the island from Poto Tano in the west through Sumbawa Besar and Dompu to Bima in the east. The island is also a transit point for travellers heading to Komodo, Flores, and beyond — the ferry from Sape (near Bima) to Labuan Bajo on Flores passes through the Komodo National Park waters.