With the purpose of determining the microbiological properties of the soils of La Yeguada Reforestation Project, the following microorganisms were searched: aerobic bacterias, anaerobic bacterias, actinomycetes and fungi. The plots sampled were previously classified according to their productivity level (cubic meter of pine tree made per year, according to a preliminary study) in high productivity (> 15 – 20 m3/year), medium productivity (10 – 15 m3/year) and low productivity (5 – 10 m3/year). Moreover, a group of plots that have never been reforested was sampled. On the whole 15 samples were taken, 3 high productivity areas samples, 4 of average productivity, 4 of low productivity and 4 of the control group. The samples were marked and taken to the CRUV (Universidad de Panamá) microbiology laboratory, where they were analyzed. The data showed that all groups of microorganisms (fungi, aerobic microorganisms, actinomycetes and anaerobic bacterias) did not present significant differences; it means that these microorganisms were not affected by the soil conditions created for the pine trees. Also, a correlation between the development of actinomycetes and anaerobics bacteria was detected, which suggests a possible relationships between both types of microorganisms.