Approximately half of the collection consists of books, including some in Chinese. The other half of the collection is split between correspondence, mostly from Harold Thomas to his sister Margaret and her husband Walter, and subject files, which may have been compiled as Thomas, Sr., and his descendants wrote histories about the family and Hwa Mei Hospital. There are also various diplomas and medical licenses.

Approximately half of the collection consists of books, including some in Chinese. The other half of the collection is split between correspondence, mostly from Harold Thomas to his sister Margaret and her husband Walter, and subject files, which may have been compiled as Thomas, Sr., and his descendants wrote histories about the family and Hwa Mei Hospital. There are also various diplomas and medical licenses.

Most of the letters are from Harold Thomas, Sr., to his sister and her husband. A few, from 1927-1928, are from Harold Thomas, Sr., to Gertrude Thomas when she traveled to India for medical treatment.