Tuberculosis (TB) is still an endemic disease in Malaysia. Cystic lung disease in post primary tuberculosis is not common. It can occur before, during or after completion of anti-TB treatment. Clinical history and review of serial chest radiograph is paramount to make the diagnosis. This case report highlights an interesting case of a young female patient who developed extensive cystic lung disease during the course of anti-TB treatment and the importance of recognizing this unusual manifestation.