Carroll Cotton, 73, flew from Halifax to Puerto Vallarta on Monday to meet a friend, Blanca Crane, also of British Columbia. She called a relative in Vernon, B.C., at suppertime that day to say she was alone and the airport was closing.
Her daughter, Ann Cotton, who lives in British Columbia, said her mother checked into her hotel once but then signed out. No one has heard from her since.
"My Mom calls Grandpa daily and he hasn't heard from her since that phone call. Blanca has been staying at a hotel nearby and has been going to the airport to keep looking for Mom and hasn't found her," she said.
Cotton said Crane has posted signs around the city and listed her mother as a missing person with Mexican authorities.
The family has alerted the RCMP in Nova Scotia and the Department of Foreign Affairs in Ottawa.
A spokeswoman with Foreign Affairs said consular services are being offered to the family.
Cotton moved to Nova Scotia after her brother was diagnosed with cancer.