The direct estimation of ⁹⁰Sr by β counting from a mixture of other β and γ emitter is often difficult due to the efficiency variation among the β-emitters and the unknown nature of the sample. This paper deals with use of a combination of β and γ spectrometry measurements in estimating the activity of ⁹⁰Sr, pure  β emitter from a mixture of other β–γ emitters in water samples. This procedure offers a simple, easy to use, rapid and a reliable method for ⁹⁰Sr estimation as an alternative to the tedious radiochemical separation procedure in this specific case.