The 26 year old made thirty-four Premier League appearances for Cardiff City last season having signed from Sevilla twelve months ago but was unable to help steer them to safety.
The South Wales side are now set to complete a deal with the Serie A giants today, with Medel having already given the green light to an offer of a 5 year contract worth around £1.75m a season.
Inter had initially been keen to secure his services on a temporary basis, though Cardiff owner Vincent Tan is holding out for a permanent deal.
The defensive midfielder took his international appearances tally to sixty-one caps playing as a centre-back for Chile at this summer’s World Cup finals, starting all four of their matches in Brazil.
Inter finished fifth in Serie A last season, and can be backed at 14/1 to end the 2014/15 as champions.