Hi,
I would like to invite my parents from Nepal for a short visit. I'm currently in F1 status (Grad student). My question is :
What are the documents I need to prepare?
If anyone of you already invited your parents, please share what documents you prepared.
Thank you for help!

Invitation letter, your I-20s(including current one) and pay stub should be enough. It depends on why you want to call them-Graduation, assistance for pregnant wife or just a family visit.

Thank you, Hydrogen Sulphide!!

My mother in law got visa 3 weeks before. In addition to above documents, you can also send you certificate of enrollment (something to show how many semesters you have attended). You department can help you with that..It proves you are studying here now..And if you intend to cover their cost in US and will mention that in invitation letter, its better to show some bank balance in US too.. I showed around 5000. Also , on your parents side they may need to show proof of their work/ bank account/lalpurja etc. Also, send a copy of your I94 and visa page . You can actually print it online.

But if you are inviting them for graduation, i think things are simples. In my case, i just invited her for visit.

Suraj2062 makes a good point. An applicant for a non-immigrant visa must show (among other things) that they have an un-abandoned foreign residence, and that they have "non-immigrant intent." It is more important to show why they are going to go back at the end of the trip than why they want to come.

Good luck!

Jamie Gorton
Law Offices of Jamie Gorton - (800) 655-0347

Thank you @ suraj 2062 for sharing, and wonderful suggestions. I requested to international office for enrollment verification.
Thank you Gorton Law for your important point.....