His post graduate specialisation was in psychiatry at Yale University (USA) which was followed by working as a consultant psychiatrist within the Department of Health.
He represented the Nationalist Party in the Medical Board for the Maltese Electoral Commission.
Following Dalli's resignation from the post of Minister for Social Policy, the portfolios of Health, Elderly and Community Care were assigned a Ministry.
Cassar became the Minister for Health, Elderly and Community Care on 9 February 2010.
Mario Galea, retained his own position as Parliamentary Secretary for the Elderly and Community Care.