The main public bus option from San José is with MEPE (Empresa de Transportes Caribeños), which runs direct services to Cahuita from the Terminal del Caribe in San José. The journey takes around 4.5 hours on a good day, though the road through the mountains can slow things down. Buses also run frequently from Puerto Limón, about 43 km to the north, in around one hour. The Limón connection is useful if you are arriving on the Caribbean coast and hopping between towns.
Shuttle services from San José and popular Pacific coast destinations are available through operators like Interbus and Caribe Shuttle. These cost considerably more than public buses but drop you off at your accommodation and are worth considering if you are travelling with luggage or a tight schedule. There is no domestic airport near Cahuita — the nearest commercial airport is Juan Santamaría in San José.