If you are not too much after comfort and want to fully experience Khao Yai park, staying within it is probably the best thing to do. Meanwhile it can be hard to book for foreigners and the choice is limited, so if you experience trouble with booking you can as well try your luck at arrival, if there is place left, specially during week days, I don ‘t think it will be a problem.

Accommodation choices range from :
Youth hostel:(location zone 1, visitor center area) large lodges and dormitories are available for rent, some with no mattress, for large group from 20 to 50 peoples for school and students large groups.

Bungalows in Suratsawadee

Bungalows: (location zone 3, Suratsawadee zone), 2 large compound offer about 20 fan rooms for 2 at 800 thb per night
Lodges: Large, nicer and more secluded lodges for 6 people up to 28 start at 2000 thb up to 9000 thb per night:

Zone 1:Kong Kaeow area near the visitor center: 4 lodges for up to 8 people at 2400 Thb.

Zone 2: Orapim:3 lodges for 8 peoples 2400 Thb and Trewtat, 2 lodges for 6 people 2000 Thb.

Trewtat lodge for 6

Zone 4: Sumnuk Naiyok. 4 nice lodges for 4 people, 3000 Thb, (bung. ref 401 to 405, Sumnuk Naiyok). Rattamontree, Tanarat zone, 2 lodges for 6 at 3500 Thb

Still in zone 4, Tanarat zone, the terrace house have 4 rooms for 2 and 4 rooms for 4 which can be book individually for 800 and 1200 Thb per night.

Camping: There is different camping sites in the park, quite nice actually, with grassland areas and small lakes close by.

Lum Ta Klong camping site

Camping fee is 30Thb. per person if you bring your own tent, prices for tent rental and camp fee: from 250 Thb. to 800 Thb. per tent depending of the area and the tent size ( for 2 up to 4 people in a  large tent), you can also rent sleeping bag, matelas and pillows and cover for 150 to 200 Thb per night/ set. Some restaurants and shops are available near by for dining. You can rent some tents and get more informations at the park headquarters.

ranger station camping site

Camping sites: near the headquarter area, 2 sites are available here: Lum Ta khlong & Pha Kuai Mai.

Another camping site is located at the ranger station 4 area, Khlong Pla Kung

General notes: getting your own way of transport is a must have to stay in the park, some accommodations can be quite far from the entrance or the headquarters
For camping, keep in mind this is a very popular option with Thai students specially on week-end so u might not experience the serenity you might expect.

Sumnuk Nayok Lodges

Lodge and rooms booking: As you need to book threw transfer it s not always the easiest thing to do for foreign tourists, booking can be arranged through the park website or by telephone: DNP booking at +66 2562 0760. Reservation can be made 60 days in advance. Payment at Krung Thai Bank Public Company Limited, needs to be done within 2 days after the reservation is being made.
Foreign clients who perform on-line accommodation booking from outside Thailand must transfer the accommodation fee (except bank service charge) to Krung Thai Bank Public Company Limited, Thailand, account number 039-6-02816-0. ( You can transfer cash to a bank account easily from any transfer machines in most dedicated ATM/banks)
It is important to e-mail The Department of National Parks, Wildlife and Plant Conservation to np_income@dnp.go.th with the following information : 1) Booking Code. 2) Name of booking person as shown in the booking information. and 3) Name of National Park that has been booked.
DNP Website: National park of Thailand, Khao Yai accommodations

Check more about what to see and do inside Khao Yai national park