The aim of this paper is to analyze both the term structure of interest and mortality rates role for evaluating a fair value of a life insurance business. In particular, a fair value accounting impact on reserve evaluations is discussed comparing a traditional deterministic model based on local rules for an Italian balance sheet calculation and a stochastic one based on a diffusion process for both mortality and financial risks. As proposed by IAS Board we will separate the embedded derivatives from their host contracts, so the fair value of a traditional life insurance contract would be expressed as the value of four components: the basic contract, the participation option, the option to annuitise and the surrender option. A numerical application to a traditional Italian life insurance policy is discussed.