There is a global Acquired Immune Deficiency Syndrome (AIDS) epidemic. It is estimated that the total number of people living with Human Immune deficiency Virus (HIV) is 33.2 million in the year 2007. An estimated 2.1 million people died from AIDS in 2007. As highly active antiretroviral therapy (HAART) becomes more widely used, the side effects of this regime are becoming more evident in clinical practice. We present 2 cases that demonstrate the association of HAART and gynaecomastia. Imaging features of gynaecomastia and the differential for these changes will be reviewed. Proposed mechanisms for the pathogenesis of gynaecomastia will be discussed. Possible therapeutic options will also be briefly considered.