Abstract: The present invention relates to a steerable catheter assembly, comprising an elongate outer shaft having a lumen therethrough and having a proximal end and a distal end; an elongate inner shaft coaxially disposed within the lumen of the outer shaft and having a proximal end and a distal end; and characterised in that at least one of the inner shaft and the outer shaft is formed with a curvature at a distal portion, such that in an aligned configuration, a distal end of the catheter assembly is disposed at a maximum deflection angle ? to a longitudinal axis of the catheter assembly; and the inner shaft and the outer shaft are rotatable relative to one another out of the aligned configuration such that each shaft exerts a deflection force on the other shaft to deflect the distal end of the catheter assembly between ? and 0 degrees to the longitudinal axis of the catheter assembly.