This paper presents an experimental investigation on the flexural behavior of reinforced concrete slabs under one way bending. Sixteen simply supported slabs of dimensions 1000mm×450mm×50 or 70mm were manufactured and tested. Twelve slabs were constructed using self compacting concrete (SCC) and four using conventional concrete (CC). Four variables were adopted to investigate slabs behavior: type of concrete (CC or SCC), longitudinal steel ratio (ρ), slab thickness (t) and steel fiber ratio (Vf). Test results showed that slab thickness (t) was the most effective factor in increasing ultimate load (Pu) of SCC slabs (up to 111%) as compared to the longitudinal steel ratio (ρ) and steel fiber ratio (Vf) with ΔPu up to 64% and 75%, respectively. Results also showed that using steel fiber in SCC up to 0.8% reduces its filling and passing abilities but it still satisfies the requirements of SCC specifications. In contrast, steel fiber increase compressive strength and modulus of rupture of SCC up to 10% and 60%, respectively.