Abstract: A cart for transporting a portable tank, such as a tank containing fluid and/or gas is disclosed. The cart enables transportation of large heavy tanks by a single user in a highly ergonomic manner. In an embodiment, the cart comprises a cart frame, wheels coupled to the cart frame, a tank-supporting cradle, a first actuator, a retainer, a control system and a power source. The cradle is movably secured with respect to the cart frame and movable by the first actuator between upright and inclined positions. The tank can be easily transported when the cradle is in the inclined position. The retainer captures the tank on the cradle. A second actuator may be provided to operate the retainer to capture the tank. The control system powered by the power source may operate all aspects of the cart including the first and second actuators.