Parkinsonism indicates a clinical syndrome involving tremor at rest, rigidity, bradykinesia, flexed posture, loss of postural reflexes and the freezing phenomenon, caused by the disorder of the structure or function of motor pathways of the basal ganglia. Although the most common cause of parkinsonism is Parkinson disease (PD), a number of other diseases and pathological conditions can also be the cause. These states are jointly called secondary parkinsonism. Drug-induced parkinsonism (DIP) is the most common form of secondary parkinsonism. Drugs that usually induce DIP are typical antipsychotics. However, atypical antipsychotics, gastrointestinal prokinetic drugs, calcium channel blockers, antiepileptic drugs as well as many other medicaments may also be the cause. Parkinsonism caused by cerebrovascular disease (vascular parkinsonism) is the second most common form of secondary parkinsonism, with heterogeneous clinical features, pathophysiology and changes in the MRI. Many viruses are associated with the development of parkinsonism. Traditionally, influenza virus, but recently HIV, Epstein-Barr virus, Cytomegalovirus, and many other DNA and RNA viruses have been known to cause parkinsonism. Various toxins are also known for their ability to induce parkinsonism, and the most common are carbon monoxide, manganese, MPTP, methyl alcohol and cyanide. Liver and kidney failure as well as thyroid and parathyroid glands diseases may present with a clinical picture of parkinsonism and cause a differential diagnostic dilemma to the PD. Since it is difficult to distinguish secondary parkinsonism from PB based only on clinical symptoms, there is confusion in practice and antiparkinsonic drugs are unnecessarily prescribed to patients. To avoid diagnostic and therapeutic mistakes, detailed medical history and further diagnostic procedures are necessary.