A procedure was developed for complex analysis of γ-emitting nuclides and ⁹⁰Sr in natural and wastewaters with two methods of preparation of counting samples for ⁹⁰Sr activity measurement: coprecipitation of ⁹⁰Sr with strontium sulfate and coprecipitation of ⁹⁰Y with yttrium hydroxide. Strontium-90 is concentrated on KU-2-8chs strongly acidic sulfonic cation-exchange resin in the Н+ form after removing γ-emitting radionuclides on complex selective sorbents, which are simultaneously counting samples for measuring the activity of γ-emitting nuclides. The main steps of the sorption procedure for the complex analysis are described, and the choice of the method for preparing a counting sample based on ⁹⁰Y for current radioecological monitoring is substantiated.