BJP's Arun Singh on Monday took oath as a member of Rajya Sabha.
Singh, who was elected unopposed to the Upper House from Uttar Pradesh last week, took oath in Hindi.
He greeted Chairman M Venkaiah Naidu and other members after taking oath.
Singh was elected in Rajya Sabha by-election last week, which was necessitated following the resignation of Samajwadi Party member Tazeen Fatma, who is now the MLA from Rampur.