The gas bubble displacement in non-Newtonian fluids is important in many applications, including bioreactors, food processing and drilling and cementing of oil wells however a few studies have investigated this issue. The motion of gas bubbles in a viscoplastic fluid, modeled as a Herschel-Bulkley fluid, is analysed in the present work. A bidimensional approach was used, approximated by parallel plates. The multiphase flow was numerically simulated using the finite volume technique VOF (volume of fluid), which solves the conservation equations of mass and momentum coupled to an equation for the volume fraction of the fluids. Is was investigated the influence of factors such as fluid yield stress, bubble size, number of bubbles rising in the viscoplastic fluid and also the distance between them. The results indicated that the yield stress has great impact on the bubble rising velocity. In the case of multiple bubbles flowing it was also observed that the displacement of one bubble influences the rising velocity of the others, causing them to join together. As the distance between the bubbles increase the interference is eliminated and the bubbles flow separately. Furthermore, it was found that there was an wall interference depending on the size of the bubble. Lastly, it was analysed the change in the shape of the bubble. It could be observed that for lower Reynolds number the bubbles presented an spherical shape and as this parameter increases it turns into an elipsoidal shape. The qualitative results of the present study agreed relatively well with experimental works found in the literature.