Tacitus is the only Roman historian who devoted his works to such an extent to Rome’s eastern neighbor – the Parthian Empire. Scholars have researched the problem of Tacitus’ attitude towards the Parthians on many occasions. It seems that what is the most important question is not Tacitus’ opinion, but the perspective from which he looked at this topic combined with the source he used when describing the Parthians and their history. Another interesting question is also how deep Tacitus’ knowledge was of the past of the Parthian Empire and the history of Roman-Parthian relations. The aim of this paper is to verify what Tacitus wrote about the Parthians throughout his works. Without taking into account all this evidence, it is not possible to propose a proper evaluation or balanced observations concerning his presentation of the Roman-Parthian relations and internal history, society and customs of the Arsacid state in the first century CE