The paper discusses the treatment of proverbial wisdom in Polish graffiti by drawing upon nearly 100 paremic structures collected on Polish Internet sites in the last decade. Proverbs in mural writing are classified as existential graffiti inscriptions due to their general rather than individualized reference. Graffiti writers challenge the potential of universal application of proverbs, paraphrazing the original forms, creating anti-proverbs in the process, with an eye to exposing the limited application of paremic wisdom or rejecting proverbs as entirely unsuitable in the context of modern Polish society. The paper explores the ways in which humour is employed in the use of proverbs in Polish murals.