Venous thromboembolism (VTE) may represent a serious complication in the treatment of hospitalized psychiatric patients with a reduced movement. Immobilization due to a physical restraint, pharmacotherapy with antipsychotics and/or benzodiazepines, a total reduction of mobility, obesity, and dehydration may participate in etiopathogenesis of VTE. We prospectively followed individuals with a reduced mobility hospitalized at an acute psychiatric admission ward. Forty-four patients (women N = 9) with a reduced locomotion for eight hours at least presented the study sample. VTE prevention in the naturalistic setting was compared to the our previously published guidelines for VTE control in every case. The observed VTE prevention was found to be in accordance with the published guidelines in 55% of cases (N = 24). Low molecular weight heparin (LMWH) was applied to 25% of immobilized patients (N = 11), according to their grade of VTE risk. After the analysis we adjusted the VTE prevention algorithm based on our clinical experience, knowledge on the observed cases, and new literary evidence. The new version of recommended procedures (physical exercises of lower extremities, sufficient hydratation, graduated compression stockings and administration of LMWH in high risk patients) is more simple, and makes the decision on VTE prevention in hospitalized psychiatric patients easier.