Mount Roskill Grammar School offers sports, music and other extracurricular activities. There are culture groups relating to
Indian,
Chinese,
Japanese,
Kapa haka,
Tongan,
Samoan,
Tokelauan,
Niuean and
Cook Islands culture. The Indian Dance group won the 2007 Annual Bollywood Highschool Dance Competition. The Boys Chorus (Mr G's Boys Chorus) was actively involved in
Barbershop Music, winning a record of 5 consecutive Auckland Regional titles in 2002, 2003, 2004, 2005, and 2006 as well as the New Zealand National Young Singers in Harmony Championships in 2002, 2005 and 2006. The school at that time was the only school in New Zealand to have won 3 National Championships, and 2 consecutively.
Houses As of 2017, Mount Roskill Grammar School has 5 houses that have been named after famous New Zealanders -
Rutherford (Red),
Ngata (Orange),
Sheppard (Yellow),
Hillary (Green) And
Cooper (Blue). Junior students are placed into house groups through their core classes, senior students remain in the houses they were in during year 10. ==Awards==