A procedure for obtaining iron which is both convenient and reliable is described. The procedure involves shaking the samples overnight in a citrate‐dithionite buffer. This is followed by a colorimetric iron determination using orthophenanthroline. The use of an automatic pipette, a flocculating agent, and noncritical quantities of dry reagents facilitates the determination. The results show increased effectiveness and reliability over Kilmer's porcedure for high‐iron Oxisols and Ultisols from Puerto Rico.