Among his other appointments Ainsworth was a Visiting Professor at the École Polytechnique Fédérale de Lausanne. He was a member of the Science Review Panel which advised the Irish Government on the funding of universities; a technical evaluator for the NATO Advisory Group for Research and Development; an advisor to Oxford Catalysts Group plc; a member of the Engineering and Physical Sciences Research Council; a member of the British Association for the Advancement of Science; a member of the Oxford Philomusica Advisory Council; Chairman of the Hinksey Fields Protection Group; Chairman of the Broad Street Plan Group of the Oxford Preservation Trust; and a trustee of the Oxford School of Drama.