Hello friends,
I came to USA two years ago. My wife is a US citizen. I have a green card and don't plan to be a citizen. We got married in Nepal. She sponsored for me. I came after a year we got married. Her parents are in USA. My parents are in Nepal. They don't want to immigrate here. I want to invite them to visit. I don't know what the best course will be. Can you please suggest how to get them here?

You can get a letter from a medical doctor stating that your wife is pregnant and your parents being here will help and empower her during this process! I think then they will be more successful getting a visa

My wife is not pregnant. Is it not possible to invite them to visit and still get a visa? What documents do i need to send them from here?

If it's just for visit, then they need to submit documents which can prove ties to Nepal (meaning they will return to Nepal) financials, lalpurja, business (if any) etc ...I think it's much more difficult to get a visa without a probable cause such as college graduation, pregnancy or illness but you can try it and see what happens
From your side you just need to send your bank statements, account information n recent W2 tax and a letter stating you'll take care of their expenses while they're here in the US

Ok. Thanks micro! The thing is we have joint income of only $30k in 2015 and 10k in 2014. Should i just send the tax return of 2015?

fresh, your combine incomer around $ 30K may not be strong enough, if your parents run business or high officer in Nepal (I meant they make good money there ) then its likely more chance to get visit visa.Usually, they evaluate by considering every aspect and I guess they keep track because lots of Nepali visitor stay here and file asylum. Sometime LUCk also works. so you can try i think there is not much cost involve.

Thanks submark. Will try luck!