Beulah Washabaugh, 67, a retired supervisory statistician at the Bureau of the Census, died of leukemia Thursday at the Southern Maryland Hospital Center in Clinton. She lived in Washington.

After completing work on the 1960 census, Mrs. Washabaugh worked with the bureau's International Statistical Programs Center. She directed the preparation of case study manuals on censuses and surveys. The materials were used extensively in training programs at the bureau for statisticians from developing countries and at international training centers.

She was considered an authority on procedures and methods used in data collection, processing and analysis. She had received the Commerce Department's Silver Medal in 1966 and recently was nominated to receive its Gold Medal.

She retired last February, but continued to serve the Census Bureau as a consultant.

Miss Washabaugh was born in Mount Pleasant, Pa. After graduating from Thiel College in Greenville, Pa., she taught in the Greenville school system.

She joined the Census Bureau here in 1940 to work on processing the results of the 1940 census of population and housing. She then worked as a survey statistician with the population and housing divisions.

Miss Washabaugh was a member of the international Statistical Institute, the Inter-American Statistical Institute and the International Association of Survey Statisticians.

She is survived by five sisters, Lela Washabaugh of Washington, Mabel McCaffrey of Orlando, Fla., Sarah Beranek of Dawson, Pa., Dixie Connors of Ligonier, Pa., and Elsie Yanchulis of Rockville, and three brothers, Francis, of Atascadero, Calif., John, of Greensburg, and Donald, of Washington.