Pieter Hendrik Mullaard was born in Rotterdam, in the Netherlands. Over the course of his life, he lived and worked in Hillegersberg, Ermelo, Groningen and Bilthoven.
Piet Mullaard was autodidact; he worked as a painter and sculptor. He took up painting about 1936 and continued until 1980 when he completed his last painting following a visit to Canada. He left a collection of about 150 paintings and 25 sculptures, most of which are now in Ontario, Canada. The online P.H. Mullaard Art Collection suggests that Mullaard painted primarily landscapes and still-lifes, but also some seascapes and portraits. As a painter, he was most productive during the years 1937 to 1962. In 2012 , Mullaard's paintings of sand dunes at Hulshorst came to the attention of the British geologist Michael Welland, author of Sand: The Never-Ending Story (2009), who included several paintings in his blog posting.