The invention relates to a rail clamp which allows a mounting rail to be clamped to a mounting bracket using connection formations of a rail connecting portion which also supports the mounting rail. It can be seen that the invention provides a rail clamp wherein pivotal movement of the base portion about the pivot surface causes in use a mounting rail inter-engaged with the rail connecting portion to be pivoted onto the mounting bracket thereby to anchor a free end of the mounting rail and the mounting bracket thereby to cause pivotal movement of the inter-engaged connection formations relative to each other to cause a torsional clamping action.