Nationals from Belarus, Georgia, Kazakhstan, Kyrgyzstan, Moldova and Russia can visit without a visa and stay for as long as they like.
Passport holders from Armenia, Azerbaijan and Ukraine can enter for 90 days without a visa.
Passport holders from Argentina, Australia, Austria, Bahrain, Belgium, Canada, Chile, Croatia, Cuba, Czech Republic Czechia, Denmark, Dominican , Republic Dominicana, Ecuador, Estonia, Finland, France, Germany, Greece, Iceland, Indonesia, Italy, Jamaica, Japan, Jordan, Latvia, Liechtenstein, Lithuania, Luxembourg, Malaysia, Maldives, Monaco, Netherlands, New Zealand, Norway, Philippines, Poland, Portugal, Qatar, Saudi Arabia, Singapore, Spain, Sri Lanka, Sweden, Switzerland, Thailand, Turkey, United Arab Emirates, United States and Uzbekistan can enter for 30 days without a visa.
Most other nationalities can obtain an evisa which is valid for 60 days.
If you are not eligible for an evisa you can apply for a visa using the Visa Electronc Application Center.
Tajikistan visa information
Tajikistan e-Visa
Tajikistan Visa Electronic Application Center
Tajikistan embassies