Controlled low-strength material (CLSM) is defined by the American Concrete Institute as having a 28-day compressive stength less than 1,200 psi. Its primary ingredients are portland cement, fly ash, and filler aggregate. Although CLSMs have been in use for a number of years, confusion about their construction benefits and economic savings remains. The principal use of CLSM has been as a controlled-density fill (CDF) in place of conventionally placed backfill. A method for determining the cost of CLSM-CDF and how it can affect a contractor's total construction costs is described. General technical information for the manufacture and testing of CLSM in the laboratory and in the field is cited. A small sample of ready-mixed concrete producers indicates the need for dissemination of information about CLSM.