Kep has no bus station or direct express services from Phnom Penh, but getting there is not complicated. Minibuses (shared taxis or booked through guesthouses) run from Phnom Penh and take around 3–4 hours depending on the route. The most common stop-off is Kampot, 25 kilometres up the coast, which has more frequent connections.
From Kampot, a tuk-tuk or shared taxi to Kep takes 30–40 minutes along a good road that passes through salt flats and pepper farms. Most guesthouses in Kampot can arrange a transfer.
From the Thai border at Hat Lek/Cham Yeam (near Koh Kong), it is possible to take transport south through Kampot and then on to Kep, but the journey is long and connections are infrequent — plan for a full day.