At least two Picasso paintings with a combined value of 50m euros (£33.7m) have been stolen from his granddaughter's home in Paris.
Maya with Doll is a portrait of Picasso's daughter
A portrait of the Spanish painter's daughter, Maya with Doll, and one of his second wife Jacqueline Roque were taken on Monday night, police said.
There was no evidence of a break-in at the home of Diana Widmaier-Picasso, in Paris's chic seventh arrondissement.
The organised crime squad of the Paris police force is investigating.
Maya Picasso was Pablo Picasso's second child, born in 1935 to Marie-Therese Walter, one of his many lovers.
Picasso completed the portrait of Maya, who is Ms Widmaier-Picasso's mother, in 1938.
The works of the iconic painter are among the world's most valuable - and frequently targeted by thieves.
"This is another bold move by art thieves. It will be impossible to sell these iconic works in the open market," said Charles Dupplin, art expert at specialist insurer Hiscox.
"In recent years we have seen some evidence of stealing to order in various European countries. This may well be what is happening here"
In 1989 thieves raided the home of another of Picasso's granddaughters, Marina Picasso.
They took 12 paintings worth $17m (£8.7m) at the time. All were later recovered.
In the largest theft of Picasso works, thieves stole 118 pieces from a museum in the southern French city of Avignon in 1976.
His 1905 masterpiece Boy with a Pipe is still the most expensive painting sold at auction. It went for $104.2m (£53.2m) in 2004.
Picasso died in France in 1973, aged 91.