Pseudoachondroplasia is an autosomal dominant variant of osteochondroplasia that results in mild to severe short-limb dwarfism and early-onset of osteoarthrosis. It has been linked to results from mutations in the gene for cartilage oligomeric matrix protein. We describe a 4-year-old boy with pseudoachondroplasia who also had prolapse of the mitral valve. To the best of our knowledge, this association has not previously been reported.