Martiens Louw was a member of the Springbok side led by Hannes Marais which toured unbeaten through Australia in 1971.
Louw only played in 2 Tests but played for Transvaal from 1969 to 1974. In 1971 he was a member of Piet Greyling’s Transvaal side who shared the Currie Cup with Northern Transvaal. The next year when Transvaal won the Currie Cup, by beating Eastern Transvaal in Springs, Louw could not play due to a broken ankle.
Louw also played for Veeeniging club, those days one of the stronger clubs in the Transvaal region, where he played with Gerald Bosch, Piet Bosman and Piet Botha.
Later in life Louw was a Transvaal selector and vice-chairman of the Vall Triangle Rugby Union, when they became a seperate Union. He also coached Vaal Triangle.