While sharing a picture of the script on Twitter, Gunn made sure that he was giving absolutely nothing away to his followers, reported Sreen Rant.
"Phew. 1st draft," he shared, before adding a series of hashtags that re-enforced his decision to keep a few secrets: "#GotG2 #NoSpoilers #NotEventheTitle."
The director later shared the photo on his Facebook page, adding: "After 48 days straight without a day off, the first draft of #GotG2 is done. I'm sorry to all my friends and family who I have ignored."
The filmmaker also teased what the future holds for some of "Guardians of the Galaxy" characters in a Facebook Q&A earlier this year.
Filming for the sequel will be moving away from London to Pinewood Atlanta Studios, with the shoot commencing in February 2016.
"Guardians of the Galaxy 2" is slated for release on May 5, 2017.