Much of the transportation and handling of molten sulfur requires liquid sulfur pumps which are challenging to operate due to the anomalous behaviour of sulfur’s viscosity around its λ-transition region. Sulfur’s viscosity increases from ≈ 10 cP upon melting at T = 115 °C to ≥ 90 000 cP at T = 187 °C. While the temperatures for this viscosity transition is well known, no shear related information can be found in the literature. Understanding the flow behavior of molten sulfur will allow for better pump design and/or qualification of their operational limits. The investigation of the viscosity of molten sulfur was performed using a new Anton Paar MCR 302 rheometer supplied with a 1000 bar titanium pressure cell. Viscosity profiles including attenuation during heating or cooling are discussed, as well as the rheological behaviour of molten sulfur encountered at shear rates experienced within pipe flow and/or commercial sulfur pumps.