A portable and collapsible wheelchair having an interchangeable front wheel steer configuration and a rear wheel steer configuration; and having (a) a pair of side frame assemblies (2,3) each having an upper tube member and a lower tube member and forward and aft sections; and (b) a 6 bar linkage mounted on the side frame assemblies, which linkage extends centrally between the side frame assemblies, which linkage is foldable from an extended, in-use position, to a collapsed, folded, position; (c) a pair of front wheels with each wheel being attached to the forward section of the side frame assemblies and wherein the front wheels can be converted from having no swivel ability when the wheelchair is in rear steer configuration to having swivel ability when the wheelchair is in a front steer configuration, (d) a pair of rear steer wheels that can swivel freely in a rear steer configuration and which can be converted from having swivel ability when the wheelchair is in rear steer configuration to having no swivel ability when the wheelchair is in front steer configuration, with each rear wheel being attached to the aft section of the side frame assemblies, (e) a pair of collapsible pushing handles that are attached to the side frame assemblies, (f) a pair of arm rests (36,37) that are attached to the side frame assemblies, (g) a pair of back support arms that secure a back support, wherein each back support arm is attached to the aft section of one of the side frame assemblies and (h) a seat support that extends above the 6 bar linkage and between the side frame assemblies; wherein in use the wheelchair is deployed by (i) spreading the side frame assemblies apart to extend the 6 bar linkage into a locked position and (ii) putting the pair of collapsible pushing handles into a locked in-use position and further wherein in use the wheelchair is collapsed by (i) pulling a handle proximate the central position of the 6 bar linkage to release the locked position of the 6 bar linkage to pull the side frames assemblies together, and (ii) collapsing the collapsible handles from their in-use locked position to a folded out of use position into a compact, readily lifted and transportable configuration; and further wherein the conversion between rear and front wheel steer configurations is achieved by either locking off the pivot ability in the rear wheels and enabling pivot ability in the front wheels to convert the wheelchair into front wheel steer configuration or by enabling the swivel ability in the rear wheels and removing the pivot ability in the front wheels to convert the wheelchair into rear wheel steer configuration. (a) a pair of side frame assemblies (2,3) each having an upper tube member and a lower tube member and forward and aft sections; and (b) a 6 bar linkage mounted on the side frame assemblies, which linkage extends centrally between the side frame assemblies, which linkage is foldable from an extended, in-use position, to a collapsed, folded, position; (c) a pair of front wheels with each wheel being attached to the forward section of the side frame assemblies and wherein the front wheels can be converted from having no swivel ability when the wheelchair is in rear steer configuration to having swivel ability when the wheelchair is in a front steer configuration, (d) a pair of rear steer wheels that can swivel freely in a rear steer configuration and which can be converted from having swivel ability when the wheelchair is in rear steer configuration to having no swivel ability when the wheelchair is in front steer configuration, with each rear wheel being attached to the aft section of the side frame assemblies, (e) a pair of collapsible pushing handles that are attached to the side frame assemblies, (f) a pair of arm rests (36,37) that are attached to the side frame assemblies, (g) a pair of back support arms that secure a back support, wherein each back support arm is attached to the aft section of one of the side frame assemblies and (h) a seat support that extends above the 6 bar linkage and between the side frame assemblies;