Chelsea have confirmed they have reached an agreement with Atletico Madrid to sign Diego Costa.
Chelsea added on their official website that they would meet the buy-out clause in the Spain international's contract, which is reported to be worth around 32 million pounds.
A statement on the Atletico website added: "Diego Costa communicated to us at the end of last season his wish to be transferred to Chelsea FC and today the two entities have reached an agreement for the transfer of his rights, by which the London club is obligated to pay the buy-out clause in the contract between player and club.
"We wish the player much luck in this new step in his professional career."
Blues boss Jose Mourinho made no secret of his desire to improve his strike-force last season as Fernando Torres, Demba Ba and Samuel Eto'o struggled. Eto'o, who had signed late last summer after a failed attempt to bring in Wayne Rooney, has now left the club following the expiry of his contract.
Costa scored 35 goals last season as Atletico won the Spanish league title and reached the Champions League final.
Chelsea have already brought in Spain midfielder Cesc Fabregas from Barcelona, while goalkeeper Thibaut Courtois appears set to finally play for the club after three seasons on loan at Atletico.
Defender Kurt Zouma, signed in January from St Etienne but loaned back to the French side for the remainder of the season, is also set to be part of Mourinho's squad.
David Luiz, meanwhile, has been allowed to join Paris Saint-Germain, while the club expressed gratitude to Ashley Cole, Hilario and Sam Hutchinson after their deals ended.
Frank Lampard, who is also out of contract, is expected to agree a deal with MLS side New York City FC.