Methods for manufacturing multi-lumen catheter tubes are disclosed. The described methods may be employed to manufacture a reinforced catheter tube suitable for use in power injectable and torqueable multi-lumen catheters, for example. In one embodiment, a method for manufacturing a multi-lumen catheter tube comprises first clamping a flexible sheet of catheter tube material between first and second mandrels. The mandrels may be D-shaped, or may include another suitable cross sectional profile. The first and second mandrels are rotated with respect to the flexible sheet so as to wrap the flexible sheet about the mandrels. Adjacent portions of the flexible sheet are joined along a longitudinal length thereof to define a closed catheter tube including first and second lumens. The first and second lumens may conform to the D-shaped profile of the respective mandrels.