The minerology of the clay fraction of different soils of the Republic of Panama is determined due the importance of knowing the type of clays present for the taxonomic classification of soils.  The soils selected for this mineralogical analysis are of agricultural and research importance.  The results of the clay minerals determination on each of the soils analyzed are presented in the following decreasing order.  Soil 1 Faculty of Agricultural Science - Chiriqui series (Kaolinite, Gibbsite and Goethite); Soil 2 Buena Vista (IDIAP), Colon, (Montmorillonite); Soil 3 Salud, Colon (Gibbsite, Kaolinite, Goethite); Soil 4 Pacora (Felipillo), Panama (Kaolinite and Gibbsite traces); Soil 5 El Ejido (IDIAP), Los Santos (Kaolinite, Vermiculite and Montmorillonite); Soil 6 Tonosi (under rice cultivation), Los Santos (Vermiculite); Soil 7 Gualaca (IDIAP), Chiriqui (Kaolinite, Gibbsite and Goethite).  Each soil was characterized physical and chemistry wise with the objective of gathering fertility information and indicate its use in future projects, as a complement to the information obtained in the mineralogical determination.  The clay mineral identification present in the soils was made possible with the use of the X-Ray diffraction technique.  For the analytical procedures used to separate the clay fraction the methods indicated by Jackson (1969) were followed.  In order to facilitate the interpretation of the X-Ray difractograms and thus the clay identification they were saturated with magnesium saturated and solvated with glycerol and potassium heated to 110° and 500° C.