Carbon steel fibre reinforced lightweight aggregates (LWA) were produced in a pilot scale rotary kiln. Narrow size fractions as well as not-sieved (asreceived) material were investigated according to European standards with a main focus on strength and density and compared to a reference materialwithout fibres. Depending on the size of the pellets a fraction of the fibres oxidized during firing. A strength increase proportional to the amountof non-oxidized fibres within the pellet was observed. The crushing resistance for as received fibre reinforced pellets (bulk density 452 kg/m3) was3.0 MPa corresponding to an increase in strength of 140%. The enhanced strength was also confirmed by the single pellet compression test.