Jiri Vana, 37, has gone missing after heading to Bulgaria to hike in the mountains, Bulgarian police say.
According to his mother, quoted by the Interior Ministry, he left the country on May 26, saying he intended to go to several Bulgarian mountains such as Rila, Pirin and Stara Planina.
His return ticket was dated June 19, but he never returned, his mother says. He was to take another flight to Peru on June 22.
Bulgarian authorities have been informed by their Czech counterparts and asked for assistance.
Police confirm he entered the country on May 26, 2016, at 18:21 local time, landing in Sofia.
Daily newspaper Trud reports Mr Vana's friends have also contacted the media outlet's Facebook page asking for assistance. They have described him as 180 cm tall, wearing a backpack and moving around with a camera and a video recorder.
Those who have seen or contacted the person in question are asked to call 112 or the nearest police unit.