Determination of creatinine concentration in biological fluids is becoming increasingly relevant as a clinical test. Various chemical and physico-chemical methods have been proposed to determine creatinine concentration in biological samples, including various modifications of the well-known Jaffe color reaction, although it has several drawbacks, namely, a low specificity and sensitivity to positive and negative interference from related substances. In addition, the available methods are time consuming, require a complicated sample preparation procedure, expensive reagents, highly qualified personnel and, most importantly, do not allow real-time analysis. Therefore, increasing attention has been paid to enzymatic methods for the determination of creatinine, particularly, using microbial creatinine deiminase. In this regard, the search for new microorganisms – effective producers of specific creatinine deiminases – is an actual task for microbial enzymology and analytical biotechnology. We have analyzed creatinine deiminase activity for 10 strains of different molds: Botrytis aclada , Botrytis allii 100(5), Monilinia fructicola , Sporobolomyces salmonicolor , Totula sp., Stachybotris chartarum , Pichiapini , Aspergillus oryzea , Trichoderma lignorum , Aspergillus glaucus , Trichothecium roseum , Aureobasidium pullulans . Among the strains tested, the enzyme activity was detected in the following species: M. fructicola, A. pullulans, B. allii, T. roseum, and C. g lobosum , although only two fungi, B. allii and C. globosum , were able to use creatinine as the sole nitrogen source. Creatinine deiminase activity in cell free extracts of B. allii and C. globosum , grown in glucose medium supplemented with creatinine (as the sole carbon and nitrogen source, respectively) was 2.5 and 1.5 times higher, related to that for the strains grown in glucose-sodium nitrate medium. Therefore, the fungi B. allii and C. globosum can be used for isolation of creatinine deiminase to be used in construction of biosensors selective to creatinine.