The Rev. Daniel do Carmo Sr., 77, a retired chief of the Portuguese section at the East Coast branch of the Defense Language Institute, died of congestive heart failure Dec. 26 at Alexandria Hospital.

An ordained Baptist minister in his native Brazil, Mr. do Carmo also served as an Interim pastor at the Northside Baptist Church in Hollywood, Md., and at the Carmody Hills Baptist Church in Carmody Hills, Md., in 1964. He was pastor at the Brookmont Baptist Church in Washington for several months in 1967.

Mr. do Carmo was born in Rio de Janeiro. He earned degrees at the Rio Baptist College and the Rio Baptist Seminary and was ordained in 1927. From 1928 to 1931, he studied in the United States and then returned to Rio de Janeiro, where he was a pastor and a teacher at Rio Federal University.

He came to the United States about 1940 and worked briefly at the State Department before joining the faculty of Johns Hopkins University. He joined the East Coast branch of what is now the Defense Language Institute in 1946 and was head of its Portuguese section at the time of his retirement in 1967.

Before and after 1969 to 1971, when he lived in Jacksonville, Fla., Mr. do Carmo had been a resident of Alexandria for many years.

His first wife, the former Helen Gibson, died in 1960.

Survivors include his wife, Ruth K. do Carmo, of Alexandria; four children by his first marriage, Daniel Jr., of Orlando, Fla., Finley G. of Laurel, William N., of Toms River, N.J., and Winston G., of Alexandria; a brother, Paul, of Rio de Janeiro; Seven grandchildren and one great-grandchild.