Born on March 16, 1945, in Lüdenscheid, Hajo Gies initially studied sociology in Frankfurt am Main. His university professor was Theodor W. Adorno.

In 1967, Gies was accepted at the newly-founded Academy for Television & Film (HFF) in Munich, where he studied until 1971. His teachers included Douglas Sirk. Alongside directors such as Wim Wenders, Gies was one of the first HFF graduates ever. In 1972, his graduation film "Nocturno" was screened at the Locarno International Film Festival. Instead of pursuing a big screen career, Gies made a name for himself as a director of unusual TV crime movies. By now, his "Tatort" episodes "Das Mädchen von gegenüber" (1977) and "Der Feinkosthändler" (1978) are regarded as classics of the series.

However, Gies scored his biggest coup in the 80s when he invented the character of the "Tatort" police inspector Horst Schimanski, brilliantly portrayed by Götz George. In 1985, the unorthodox cop also conquered the big screen. While the movie "Zahn um Zahn" attracted three million viewers to the cinemas, the sequel called "Zabou" could not follow up this success. Aside from shooting numerous "Tatort" movies, Gies - who ranks among the busiest German TV directors – has also directed several episodes for the successful detective drama series "Kommissar Rex" ("Inspector Rex") as well as television plays such as the romantic comedy "Alpenglühen", in which the leading role was once again played by Götz George.

After a series of other TV films that can be classified as light entertainment, Gies shot the German-German TV drama "Heimweh nach drüben" in 2007. With Wolfgang Stumph, Katrin Sass and Jürgen Tarrach in the leading roles, it tells the story of a citizen of the GDR who involuntarily gets caught between the fronts of the East and West German secret services during a stay in the West. Following this, Hajo Gies returned almost exclusively to directing television crime dramas, including several successful episodes for the popular "Tatort" series. In 2007, he also directed the episode "Bunte Bonbons" for the children's crime series "Krimi.de", which won the Children's Jury Award at the prestigious Goldener Spatz children's media festival.

Hajo Gies's last directorial works were two episodes of "Mord in bester Gesellschaft" in 2012/2013, a crime series aired on ARD, starring Fritz Wepper and his daughter Sophie Wepper in the lead roles. After that, the then 68-year-old Hajo Gies retired.