A technique has been developed for the determination of 227Ac concentration in soil samples. Emanating 219Rn is introduced into an air stream and passed through a two-filter decay tube similar to that reported by Thomas and LeClare for 222Rn [Health Phys. 18, 113 (1970)]. Experimental tests and theoretical calculations indicate the technique to be sensitive at a level of 2 pCi/g with a 95% confidence level. Relevant empirical and theoretical considerations are discussed.