You must possess a valid National Passport or International recognised travel document to enter Sarawak, Malaysia. You can also use a Document in Lieu which you can apply from Malaysian Representative Office abroad.
If you need a visa to enter Sarawak, Malaysia you must apply and obtain a visa in advance at the Malaysian Representative Office closed to you. This visa is an endorsement in your passport or other recognised travel documents, indicating that you have applied for permission to enter Sarawak, Malaysia and that the permission has been granted. But this is not a guarantee that you will be allowed to enter the country as the final decision lies with the Immigration Officer at the entry Point.
You can check with the Malaysia Immigration Department if you required a visa to entry Malaysia.
Upon arrival at the gazette entry points, you are required to complete the Arrival/Departure form (Imm.26) and present the duly completed form together with your passport to the Immigration Officer on duty. The officer must ensure that your passport or your travel document is endorsed with the appropriate pass before leaving the Immigration Counter.
You can stay up to 30 days, and you can apply for an extension at the nearest Immigration Office should you required one. This requirement is applicable to tourist coming to Sarawak. There is different requirement if you intent to work or do business in Sarawak. You can get the required information from the nearest MalaysianRepresentative Office in your country.
Malaysia has a strict anti-drug trafficking law and those caught smuggling illegal drugs will be punished accordingly including a mandatory death penalty.