The article focuses on legal insecurity under different forms of real estate lease contracts, present in contemporary Serbian law. Applying dogmatic and comparative legal methods, the authors explore the characteristics of domestic legal regime of real estate lease contracts, with special emphasis on possible application of rules of other nominate contracts to real estate lease contracts. In contemporary Serbian law only real estate financial leases are regulated, while other forms of real estate leases are not. Potential problems stemming from insufficient regulation are also evidenced in court decisions related to disputes originating from one of the innominate forms of real estate leases in Serbia. The analysis of these decisions points to issues causing legal insecurity under real estate lease contracts, which could be overcome through adequate amendments and supplements to the regulations. In this article, the authors propose specific solutions for regulating real estate lease contracts de lege ferenda, which the authors conclude are the best approach for overcoming the existing shortcomings.