PMMA has a good degree of compatibility with human tissue, and can be used for replacement intraocular lenses in the eye when the original lens has been removed in the treatment of cataracts. In orthopedic surgery, PMMA bone cement is used to affix implants and to remodel lost bone.

Dentures are often made of PMMA, and can be color-matched to the patient's teeth & gum tissue. In cosmetic surgery, tiny PMMA microspheres suspended in some biological fluid are injected under the skin to reduce wrinkles or scars permanently. Dental filling materials may also be made from a combination of PMMA and other compounds. Emerging biotechnology and Biomedical research uses PMMA to create microfluidic lab-on-a-chip devices, which require 100 micron-wide geometries for routing liquids. These small geometries are amenable to using PMMA in a biochip fabrication process and offers moderate biocompatibility.

(The beads on the right hand side are produced by Jolly Tone, providing samples that represent a human organ for a famous fertility clinic in Australia.)