The sampling procedure is a crucial step in every kind of experiment. This is also true in gene expression profiling experiments, where high quality and sufficient quantity of extracted RNA plays a significant role in the experimental outcome. We have compared five different RNA extraction protocols from peripheral blood/PBMCs with the aim to define the most suitable method for the miRNA expression profiling experiments. Convincing results in terms of highest quantity and quality were obtained by the TRIzol-chloroform extraction method. The total RNA obtained using this method contained the highest portion of good-quality miRNA molecules, which was also confirmed by gene-specific real-time PCR experiments.