Yvonne Mostard is known for her stylised, lyrical, abstract works that combine emotions, memories, and poetic layers. Her sculptures are often imbued with references to literature, classical music, and spirituality.

Her work revolves around themes such as love, transience, memory, vulnerability, spirituality, and the inner experience of time. The design is subtle and understated, with a focus on the inner world and emotions. Sometimes the sculptures are semi-figurative, often human forms or parts thereof (such as hands, heads, or bodies) that are incomplete or distorted. She leaves room for emptiness, which makes the work contemplative. Mostard has a poetic and conceptual approach, using materials and forms that evoke a sense of stillness and contemplation.

Yvonne Mostard often interweaves elements from literature, art, historical events, and music, creating self-contained works with their own unique connotations. Her sculptures are characterized by their symbolic or metaphorical nature and a simple, tranquil appearance. Her work is diverse, including wood, plaster, bronze, lead, cast resin, neon, gold leaf, silver leaf, and more.

Her work is included in various collections, including Museum Beelden aan Zee, Gemeentemuseum Helmond, IKOB Eupen, Gemeentemuseum Roermond, ABN AMRO, AEGON, Maastricht UMC, and many private collections.