Describing the mechanical behavior of geomaterials, such as soils or rocks, is a challenging task that requires sophisticated numerical analysis. In fact, geomechanical problems are characterized by solid-fluid interactions, material and even possible geometric non linearities, due to the presence of large deformations. FEM analysis are an extremely powerful tool to predict the mechanical behavior of these kinds of problems, allowing to compute displacements, stress and strain fields for the solid-fluid mixture. This work presents the main features of a Finite Element toolbox coded with Scilab to simulate typical geomechanical case studies. Thanks to the large number of built-in functions, Scilab constitutes an extremely effective framework to easily implement and solve even extremely complicated sets of equations as those necessary when dealing with such coupled problems. Additionally, Scilab allows for an immediate post-processing of the results with several graphical functions. Some examples, such as consolidation problems and borehole drillings, are treated to show the capability and efficiency of the code.