The Registration Board of the Institution is required to regulate the engineering profession and matters related therewith along with the development of Professional Engineers. The Board functions independently but is subject to the general policies of the Institution. Its composition is as follows :

• Chairman- President
• Deputy Chairman, a Fellow of the Institution, nominated by the Council of the Institution from a list of three Fellows, proposed by a Committee appointed by the Council of the Institution.
• Immediate Past President
• President-Elect
• Three Corporate Members representing each of the disciplines Civil, Electrical, Mechanical and one Corporate Member representing all other disciplines nominated by the Council of the Institution.
• Seven Corporate Members of the Institution who shall be not below the rank of senior Lecturers Grade 1, nominated by the Council of the Institution, out of which one each shall be from among the academic staff members of the Engineering Faculties of the Unversity of Peradeniya, University of Moratuwa and University of Ruhuna and from the Faculty of Engineering Technology of the Open Unversity of Sri Lanka and one each of the remaining three (3) from among the academic staff members in the field of engineering of any other Institute (State or Private) conducting a four year full time Engineering Degree Programme recognized by the Institution.
• Two Corporate Members of the Institution from the state sector, holding or who have held not less than the rank of Chief Engineer or equivalent and have had a minimum of ten years post-Charter experience, nominated by the Council of the Institution.
• Four Corporate Members of the Institution from the Private Sector having a minimum of ten years post-Charter experience, nominated by the Council of the Institution.
• Chairman of the IESL Accreditation Board

A Corporate Member who fulfills the prescribed requirements of the Board and who has his/her name entered in the register at the order of the Board, is called a Professional Engineer and is to use the abbreviations PEng. after his or her name.