A study on connecting rods for internal combustion engines is proposed here. The work is based on analytical calculations of inertial and pressure forces; in order to perform an analytical study it is necessary to break the connecting rod mass into discrete parts that can be easily written into equations. Here a very simple method is often used, but there are a lot of different methods (Sesini, 1964) which are more complicated (they need a good personal computer), but far more precise. The authors developed a method that has proven to be quite precise but not too time-consuming. The results obtained were validated by the use of finite element techniques then all the parts of the connecting rod were calculated, for example against fatigue damage or instability. With the experience gained in this work a new design for the existing connecting rod was proposed. This allowed saving some mass without affecting resistance.