The paper is devoted to revealing the essence of the ALARP (as low as reasonably practicable) principle and the possibility of its use as one of the special principles in investment law. To substantiate the effectiveness and necessity of applying this principle in investment law, a method of analysis from the general to the specific is used. The first part of the paper analyzes general approaches to understanding legal principles, and presents the main positions on the issue of the relationship between legal principles and legislation. Then, using the example of specific branches of law, through the implementation of a comparative approach, the features of the application of the ALARP principle in each of them are derived. The author concludes that there is currently no structural and uniform application of this principle in law, and therefore the possibility of using it within the framework of investment law is justified in connection with the specifics of the legal relationship between the investor and the investment recipient when carrying out investment activities.