The incident happened in Patdhara area and there was fierce exchange of fire between CRPF and Maoists, said the police.
The deceased CRPF personnel have been identified as Assistant Sub-Inspector (ASI) Shishu Pal Singh, ASI Shiv Lal and Constable Dharmendra Kumar Singh.
Meanwhile, the Odisha government announced ex-gratia of Rs 20 lakh to each of martyrs' families.
Odisha Director General of Police (DGP) SK Bansal expressed condolences to the bereaved families stating that operations would continue in the area to track down the Maoists and that the sacrifice of the jawans would not go in vain.
"Unfortunately, three jawans have attended martyrdom in Nuapada. Our senior officers are on the way to the site," Odisha's Director-General of Police SK Bansal told PTI.
The operations would continue till the Maoists are flushed out, the DGP said.
Combing operations have been intensified in the area, and more teams of the Special Operations Group (SOG) and CRPF are moving to the site, said the police.