Erkin Alymbekov's daughter, Saule, told the AKIpress news agency that her father was assaulted in the staircase of his Bishkek apartment building.
The incident took place around 0100, while the lawmaker was returning home.
Saule Alymbekova said her father was rescued by neighbors and that there was only one assailant. But police believe there were at least two attackers.
Alymbekov reportedly suffered several contusions and a cranial traumatism. Prosecutor-General Kambaraly Kongantiev visited him in hospital. The motives for the assault are unclear.