This study investigates the effect of 3-dimensional (3D) fibres on the rheological properties of self-compacting concrete (SCC) using three different fibre volume fractions (1%, 2% and 3%). Two different sizes of 3D fibres with perimeters of 115 mm and 220 mm were considered. Rheological properties were determined through slump flow, J-ring, V-funnel and sieve segregation tests. The test results reveal that the addition of 3D fibres decreases the workability of the SCC. 3D fibres with a perimeter of 220 mm have a more adverse effect on the rheological properties of SCC than 3D fibres with a perimeter 115 mm. The balling effect occurred when 2% and 3% fibre volume fractions of 3D fibres with a perimeter of 220 mm were added to the mixture, compromising the workability of SCC.