His commissions include a large group portrait for the 40th anniversary of Wolfson College, Cambridge (his father Michael Mennim having been the architect of its first buildings) and Group Portrait of the Company of Merchant Adventurers of the City of York held at the Merchant Adventurers' Hall, York and a portrait of Duncan Robinson, commissioned when master of Magdalene College, Cambridge.
During the 1980s and early 1990s he worked as an illustrator and produced many film posters and book covers including the book jacket The Hitchhiker's Guide to the Galaxy by Douglas Adams., the record cover art for the Rum Sodomy & the Lash by The Pogues, the movie posters The Crow (1994 film) and Highlander II: The Quickening.
- "The College Painting" (PDF). Wolfson College Magazine. 29: 91–92. 2004–2005. Retrieved 8 December 2013.
- "Wolfson College Mural (1965–2005)". Art UK. Retrieved 8 December 2013.
- "Group Portrait of the Company of Merchant Adventurers of the City of York". Art UK. Retrieved 8 December 2013.
- "Archives: Illustrations". Peter Mennim. Archived from the original on 11 December 2013. Retrieved 8 December 2013.
- "Peter Mennim – Chronological Bibliography". ISFDB. Retrieved 8 December 2013.
- "Rum Sodomy & the Lash - Credits on MSN Music". Archived from the original on 19 December 2013. Retrieved 18 December 2013.
- Branaghan, Sim. ‘’British Film Posters – An Illustrated History’’. BFI Publishing, 2006, p. 220.