The paper investigates the performances of two portable mobile mapping systems (MMSs), the handheld GeoSLAM ZEB-REVO and Leica Pegasus:Backpack, in two typical user-case scenarios: an indoor two-floors building and an outdoor open city square. The indoor experiment is characterized by smooth and homogenous surfaces and reference measurements are acquired with a time-of-flight (ToF) phase-shift laser scanner. The noise of the two MMSs is estimated through the fitting of geometric primitives on si