The present invention relates to a mechanized bed for automatically straightening bedclothes comprising a frame (1) which on each side incorporates a trapezoidal track (2) along which there is driven a moveable carriage which on its route activates the tensor rod (7) and the pressure roller (10) such that they straighten the top bedcover (12) longitudinally and transversally from the feet to the head depositing it on the bottom sheet (13) which is provided with elastic and Velcro-type openable sticking means to attach it to the mattress cover (11a) and at the head of the bed for each of the pillows (20) there is a frame (22) containing a mobile unit (22b) that can move up and down in which there rotates a tray stretching and straightening the cover or the pillow itself and subsequently depositing it on the top bedcover (12).