A seventh stabbing victim, and a police officer who was hurt during the arrest of the suspect, were also recovering from injuries, said police.
The incident occurred at about 6:45 p.m. in the 1200 block of Barclay St. in the city's West End, and when police arrived on scene, they found the seven victims suffering various stabbing wounds.
"It's a very vicious attack and very random," said Vancouver Police Sgt. Randy Fincham.
He said an unidentified 33-year-old man was taken into custody and that the officer who was injured during the man`s arrest was treated at the scene by paramedics.
Fincham said three men and three women, ranging in age from their 20s to their 60s, were taken to hospital, and one of the women is in "very serious" condition. The other five were in serious but stable condition.
A seventh victim, a male, was treated on the scene, while the other victims were transported to a couple of Vancouver hospitals equipped with trauma bays, said Fincham.
He said police have little information on the suspect and will try to figure out why he was in the building, adding that the victims were not related nor connected in any way.
"Police will be looking into what the motive was for this vicious attack," said Fincham.
Investigators from the police's major crimes section and forensic investigators are expected to remain on the scene throughout the night.