Cemented paste backfill (CPB) is a widely used backfilling technique around the world. To ensure the safety and cost-effectiveness of this operation, it is essential to study the change in pressure drop and velocity along pipelines, for which understanding its rheological properties is required. Previous studies have developed mathematical closed-form solutions, considering scenarios that mimic the backfill placement system, from the batching plant to the underground voids, and assuming the slurry to be viscous and cohesive during flow and frictional and pressure dependent when stationary. Computational Fluid Dynamics (CFD) is a powerful prediction tool, the use of which has been increasing in the study of CPB recently. The present study aims to study the most suitable rheological model for cemented paste backfills considering its thixotropic and viscoplastic properties while analysing how these rheological parameters impact the pressure and velocity profiles of the slurry by validating existing analytical results using CFD.