Everyone except nationals of other Gulf States need a visa to enter Qatar.
One month tourist visas are issued at the Doha International Airport on arrival to nationals of 33 countries for a fee. This can be extended for another month for a small fee.
Cash is not accepted at Immigration and visas must be paid by credit card or by the Ministry of Interior's eCash card, which can be purchased at the Qatar National Bank Counter in the Arrivals Hall for an issue fee of QR20. The specified countries can be found on Qatar Ministry of Interior.
Alternatively a visa can be applied for in advance on the Ministry of Interiors' website. This will be valid for one month and is a joint tourist visa for Oman and Qatar, but must visit Qatar first. This service again corresponds to the defined 33 nationalities.
There is also a business visit visa available, that covers the issuance of single entry business visas requested for businessmen by eligible Qatari companies.
Israeli passport holders are not allowed in Qatar.
For further information please contact your nearest Qatari Embassy or Consulate prior to arrival.