The station was upgraded in 2005 and given a lift and canopies over the stairs.
Originally, Gymea was one of two crossing loops on the line, with the other being at Caringbah. The section from Gymea to Caringbah was duplicated in 1985, and under the Rail Clearways Program, the remaining sections of single line railway from Sutherland to Gymea and Caringbah to Cronulla were duplicated in April 2010.[5][6]