The widespread usage of blood count autoanalyzers has led to a major improvement in cellular hematology because of quick and accurate results found in most instances. However, spurious test results also can be observed like pseudothrombocytopenia (PTCP). In our study, we aimed to evaluate the clinical and laboratory factors associated with PTCP. Forty-six patients with PTCP and 69 healthy volunteers were enrolled in the study. Sex distribution was similar between the groups. Hospitalization, infection, the use of low-molecular-weight heparin and pregnancy increased the incidence of PTCP. Atherosclerosis and some drugs such as warfarin and calcium channel blockers were associated with PTCP, but the coincidence was not statistically significant. Antinuclear antibody positivity was higher in PTCP group (18.8% vs 7.2%; P=0.033) but anticardiolipin positivity rates were similar when compared to controls. Pseudothrombocytopenia was frequently misdiagnosed, which led to inappropiate treatments. Therefore, this situation should be kept in mind. © 2012 The Author(s).