The efficiency of poliovirus elution from fiber glass cartridge filters (K27), epoxy-fiber glass-asbestos filters (M780), and pleated cartridge filters was assessed by using 3% beef extract (pH 9.0) or 0.1 M glycine (pH 11.5). Poliovirus type I, strain LSc, was seeded into 20- to 25-gallon (ca. 75.6- to 95.6-liter) samples of treated sewage effluent and concentrated by using a filter adsorption-elution technique. Virus elution was accomplished by using either two 600-ml portions of 3% beef extract (pH 9.0), or two 1-liter portions of 0.1M glycine (pH 11.5). In all experiments, beef extract elution followed by organic flocculation was found to be superior, yielding a mean recovery efficiency of 85%, with recoveries ranging from 68 to 100%. Elution with 0.1 M glycine (pH 11.5) followed by inorganic flocculation resulted in a mean recovery efficiency of 36%. The variable range of recoveries with beef extract could not be significantly improved by varying the type of beef extract or by extending the elution time to 30 min. Second-step reconcentration of 1-liter seeded sewage effluent and renovated wastewater samples indicated that organic flocculation was a more efficient method for virus recovery than inorganic flocculation. Beef extract concentrations of less than 3% were found to be efficient in the recovery of poliovirus from renovated wastewater.