By increasing the number of tankers in the Adriatic Sea, the hazard of maritime accidents increases as well. Oil spillage in the Adriatic Sea would cause unrecoverable damage to the environment, tourism and economy. Hence the project Structural reliability of damaged oil tanker in the Adriatic Sea was initiated, with the aim to propose methodology of structural safety assessment of a damaged oil tanker in the Adriatic Sea and to set up a procedure for rational decision making for a ship in the situations requiring emergency response actions. Calculations of damage stability and longitudinal strength were made within this paper. Classification societies provide special rules for damage stability. 21 damage cases were modeled for a homogenous, fully loaded tanker. For each one of them a compartment plan and characteristic stability and longitudinal length curves were shown. The obtained results were compared to classification society rules and results for the undamaged tanker. It was shown that the tanker meets all the stability requirements, with a great margin. Maximum bending moments vary from a decrease by 68.3% to an increase by 52.47%, compared to the value in undamaged condition. Lack of information about section modulus in damaged conditions makes it impossible to get the real insight in the danger of load increase due to flooding. One way of attempting to decrease load is ballasting, but it has not always proven to be an efficient and safe solution.