The present protocol demonstrates the four component, coupling reactions of 1,3-dicarbonyl compounds, amines, aldehydes, and nitroalkanes for the synthesis of highly functionalized pyrroles using NiO NPs as a heterogeneous and robust catalyst. The developed protocol is simple, convenient, solvent free, straightforward, easy separation of catalyst and carried at room temperature. This methodology provides an alternative approach for easy access of highly substituted pyrroles in moderate to very good yields using four simple and readily available building blocks via one-pot tandem reaction with catalyst recyclability. [GRAPHICS]