Born in San Sebastián, in northern Spain, in 1958. Still a teenager he made some short movies in a super-8 camera owned by his father. Some of those movies where "El ciego" (1976), "El jueves pasado" (1977) and "Fideos" (1979). At the same time, and willing to know more about the darkests corners of the human mind, he studied psychiatry. In 1985 he got a degree in medicine in the university of the Basque Country. By that time he has become a collaborator specialized in cinema in differents newspapers and magazines like "La voz de Euskadi", "Casablanca" and "Cinema 2000". In 1986, he directed a short in 35 mm titled "Patas en la cabeza" that won an award in the international Festival of Bilbao. In 1987, after winning the Telenorte prize for another short movie, "Las seis en punta", he decided to become a professional filmmaker. He worked as assistant, editor and screenwriter in differents projects for cinema and TV. He also wrote several screenplays but they were all refused by most of production companies. Finally, in 1991, when he was desesperate for not being able to make movies, he received a call from a new production company called SOGETEL. They were interested in one of his stories titled "Vacas" about the fight of two families along three generations, from 1875 till 1936. Released in 1992 it became a big success. It won the Goya of the Spanish academy for best new director and prizes in the festivals of Tokyo, Torino and Alexandria. In 1993, he made a second movie, "La ardilla roja" confirmed his talent and also won prizes in Fort Lauderdale, Bogotá and Bucarest. His third movie, "Tierra" released in 1996, was selected for the Cannes Film Festival, the most important in the world.

In 1998 he released "Los amantes del Círculo Polar" considered his best movie by most of his fans. It also became a box-office hit with more than one million spectators in Spain. The film was also released abroad. In 2001, his fourth movie, "Lucía y el sexo", also became a huge hit and discovered actress Paz Vega who won the Goya of the Spanish academy for best new actress.

2003 was a difficult year for Medem. The release of "La pelota vasca", a documentary that portrays the phenomenon of nationalism in the Basque Country, in northern Spain, was very polemical. Actually, Medem is one of the most importants and original spanish filmmakers.
Father of Peru Medem and Alicia Medem.