A self-taught artist, Jeff Broeckx drew his first comic at age eleven. This was 'De Witte Hinde', and the text was written by his mother, Maria de Winter. He began to work at the Standaard Uitgeverij at age sixteen. While mainly illustrating schoolbooks, he rebuilt 'De Witte Hinde' in 1964 for the magazine Ohee. Together with his mother, he created the series 'Serge' in 1965 and 'Dag en Heidi', which ran from 1966 to 1984.
Broeckx joined the Vandersteen studios in 1969, where he worked fulltime on the 'Bessy' comic. He became head of the 'Bessy' production in 1970. From 1976, he also inked the stories of 'Robert en Bertrand'.
In the magazine Zonneland, he created the series 'Sloeber', again scripted by his mother. Broeckx restyled the 'Bessy' comic in 1984, and started using more ecological themes. Of this new series, called 'Bessy Natuurcommando', appeared 23 albums with scripts by Marck Meul. He started the series 'Waterland' with scripts by Marc Legendre in Suske en Wiske Weekblad in 1994. From 1998 to 2002, he created the historical comic 'Verdwaald in het Verleden'. Jeff Broeckx has illustrated the books of 'Musti' since the death of Ray Goossens. Broeckx and his wife Ingrid van Dijck have made a comic about 'Jacot en Gnork', the mascots of the Lindenhoeve children's restaurants, in 2011.