The aim of the present paper is to investigate into the imperial cult performed on Roman Cyprus, placing a special emphasis on the so-called Cypriot oath to emperor Tiberius preserved in a Greek inscription from the Aphrodite sanctuary of Paphos Vetus (T. B. Mitford, A Cypriot Oath of Allegiance to Tiberius, JRS 50(1960), 75-79). In the oath, the Cypriots swore to the goddess Roma, Tiberius and his family at the accession of the emperor to the throne in 14. After providing an overview of studies on the imperial cult and of the Cypriot oath, the present paper tackles the oath and its text from the following three viewpoints: the theoi horkioi, i.e., the guarantor deities of the oath; the oath and the imperial cult; and the context of the oath. The Cypriot oath to Tiberius, though fragmentary in part, provides us with some fascinating insights into the religious status of the emperor on the island, the rituals of the imperial cult, and the religious and political communication between the centre and the province. The elaborately structured list of the theoi horkioi not only connects the local deities with the communal and Roman deities of greater importance, but also places Augustus and his descendants into the local context of Cyprus by means of representing the first emperor as an offspring of Aphrodite, patroness of the city of Paphos and of the island as a whole. The living emperor Tiberius also received the cultic veneration of the Cypriots, though his religious status was modified 'downwards' by means of depriving him of the epithet theos and including the goddess Roma in the objects of the final clause, which would pertain to the sacrifice to the emperor. The practice of the oath was perhaps focused on the city of Paphos, which retained the Aphrodite sanctuary and (probably) that of Hestia; however, this does not mean that the Paphians drafted and performed the oath exclusively for their own purposes and that the other cities were excluded from it. The Cypriot oath is probably a 'provincial-civic' oath in which all communities on the island participated. The oath would have involved communication between the Cypriots and the imperial power (imperial agents and the emperor himself), e.g., through the supervision of the oath by proconsules and the dispatch of a delegation to the emperor. The oath, therefore, offered the occasion for a communicative network between the Cypriots in the provincial capital and other communities, imperial agents, and the emperor himself at the religious and political levels.