Every country nationals will require an visa to enter Nepal except Indian Nationalities. Visas can be obtained from Nepal embassies abroad or on arrival at Kathmandu airport (Tribhuvan International airport). We recommend you to apply a Visa prior you come to Nepal or you can simply get one at the Nepals Internationa Airport here itself on arrival but you’ll have to wait for hrs to get your visa stamped. You will need to provide your passport valid for six months(with at least one empty page), one passport-sized photo and fees in US dollars or equivalent convertible currency ( Euro, Swiss Franc, Pound Sterling, US Dollar, Australian Dollar, Canadian Dollar, Hong Kong Dollar, Singapore Dollar and Japanese Yen) Credit cards and any currencies not mentioned above are not acceptedThe visa are multiple entry visas valid for 30 days costing US$ 40. Tourists can extend their stay for a maximum of 150 days in a year (Jan 1 to Dec 31).
Please note regulations and costs regarding visas are subject to change, so its advisable to be up-to-date with the current rules.
For more info you can visit Nepals Department of Immigration : www.nepalimmigration.gov.np