Police have described the thefts, which are believed to have been carried out by the same man, as "despicable".
The incidents took place over the last two weeks in the Stobswell, Maryfield and Douglas areas.
The suspect, who is aged between 30 and 35, may be sleeping rough and travelling by bicycle.
He is about 5ft 6in tall, of thin build, with short brown or blonde hair.
PC Garrie Watson said: "These are despicable crimes.
"This man has deliberately targeted the vulnerable and elderly within their own homes, with the oldest victim being 100 years old.
"I would urge members of the public to provide us with information which would help us to identify and arrest the person responsible."
A 100-year-old woman is among the victims of a series of distraction thefts within the homes of the elderly and vulnerable in Dundee.