Achilleas has been a practising lawyer in Cyprus since 1988 advising on legal regulatory and public affairs issues.

Though a specialist in intellectual property, pharmaceutical and competition matters, Achilleas has also been active on a number of human rights issues both at the legal level and before the executive and legislative branches of the Cypriot Government. Achilleas was also called to the English Bar and holds an LLM in International Trade from Georgetown University.