Introduction. Functional diagnostics is an integral part of the main areas of clinical medicine. In emergency medical care, it is not functional diagnostic specialists who master the methods, but doctors and emergency medical assistants. The more important it becomes to record and analyze the diagnostic work of mobile emergency medical teams. Purpose of the study: to study the features of functional diagnostics in emergency medical care. Materials and methods. Data from annual reports on the work of emergency medical care departments in St. Petersburg and the Leningrad region for 2019-1023 were used, normative legal, statistical and analytical methods were applied. Results and discussion. The main methods of functional diagnostics in emergency medical care are ECG diagnostics and pulse oximetry; more than half of the approved emergency medical care standards (63.8%) require ECG diagnostics, 51.3% require pulse oximetry; every third call in St. Petersburg (35.5±2.0%) was performed with ECG registration, in the Leningrad region - every fifth call (19.7±1.7%). 44.4±21.6% of ECG studies in the Leningrad region are carried out with remote consultation. Every third emergency medical call in St. Petersburg (27.3±3.8 units) is associated with pulse oximetry. Conclusions. Functional diagnostics are extremely important and in demand in emergency medical care, which is confirmed not only by regulatory legal aspects, but also by real performance indicators of emergency medical care units.