WMD began in 1979 by serving missionaries already working in Puerto Rico. Over the years, other Christian works among the Deaf were added, some for a short term and others longer. For example, WMD had a relationship with the Cayo Deaf Institute in Belize, a Mennonite Deaf school. Further, WMD responded to requests from other organizations for consultation and help, including the Christian Mission for the Deaf founded by Dr. Andrew Foster.
Primarily, WMD supported work in the following locations: