The 34-year-old Drysdale took a break from rowing after he won gold at Eton Dorney in 2012, and only returned to the single scull last month and was then beaten in Holland and at the Henley Regatta in England.
Selectors kept the single sculls spot open and Drysdale needed to complete the time trial on Friday to earn the place in New Zealand's team for the Aug. 25-Sept. 1 world championships in Chungju, South Korea.
"It is great to have Mahe back in the team - he is a real leader and a well respected senior member of our squad," high performance manager Alan Cotter said after Drysdale completed the final selection row early on Friday.
"Mahe has been training hard and has been very focused on his return to rowing. He has earned his spot back in the New Zealand rowing team."
While not quite race fit for world class rowing, Drysdale has hardly been idle during his down time.
He completed an ironman-distance triathlon event, took part in a multi-sport race across New Zealand's South Island and also climbed Mt Kilimanjaro in Tanzania.
Drysdale has won five world titles and had told local media last month that he needed to improve by at least another 12 seconds in his race time to be in a position to challenge for the medals in Chungju.