Controlling the crack width is essential for satisfying the serviceability limit state criteria of reinforced concrete (RC) members subjected to service loads as its affects the functionality, durability and aesthetic of the structures. In the past, no investigation has been conducted on full-scale RC two-way beam slab systems to understand their cracking behaviour. The present building codes and guidelines lack explicit analytical expressions for estimating the crack width and spacing in such beam slab systems. Hence, the current research focuses on a detailed experimental and analytical investigation of the two-way slab system to understand its cracking behaviour, particularly crack initiation, propagation, spacing, and width under biaxial moments. Experimental investigation involves testing of four full-scale RC two-way slab systems, supported on beams, with different slab thicknesses and reinforcement spacing (closer and broader). During the tests, crack spacing and width are measured by applying uniform loading over the slab with a unique sixteen-point loading tree arrangement. Results from the experimental work are then compared with Indian and European standards as well as with some existing analytical models in the literature to verify the suitability of such models for the two-way slabs. In addition, a refined finite element micromodel is developed and calibrated using the experimental results to investigate the influence of parameters, such as tensile and bond strengths of concrete and stress in rebars, on crack width. Experimental results indicate that the behaviour of RC elements under one-way bending significantly differs from that under two-way bending. The crack width formula commonly used for one-way bending leads to unconservative estimation of crack width if applied for the two-way slab. It additionally suggests that developing a different analytical expression is essential for crack width calculation in two-way RC beam slab systems. Further, it is aimed that the recommendations from this research work could be helpful as an input in developing code provisions that concern the calculation of crack width in two-way slab systems in buildings, water tanks, and nuclear reactor containment structures. This seminar will discuss the literature on the topic and Experimental work done in the present study on cracking behaviour of RC two-way slab.