The collision, involving a car and a motorcycle, happened on January 6 at the intersection of Victoria Ave and Manapouri Cres in Hokowhitu, Palmerston North.
The motorcyclist was initially taken to Palmerston North Hospital incritical condition before being transferred to Wellington Hospital for further treatment.
Despite efforts to save him, the man died on Thursday.
“Our thoughts are with his family and loved ones,” a police spokesperson said.