The idea of using AI algorithms for diagnosing and detecting pathologies in the human body is currently very popular. The reason is that the artificial intelligence technologies available to researchers make it possible to analyze information almost intuitively, to detect similarities between non-obvious patterns, and find an effective solution through training on the existing research and practical experience of specialists. As a result, diagnostic decision support systems based on artificial intelligence algorithms are increasingly being used in practice. This review examines the main artificial intelligence algorithms used in modern diagnostic decision support systems and illustrates their application for the diagnosis of several key socially significant diseases. Key issues related to the application of artificial intelligence systems in disease diagnosis are also discussed. Keywords—clinical decision support systems, cognitive computing, deep learning, diagnostic decision support systems, machine learning.