The sultry Spanish actress - who celebrated the birth of her first son with husband Javier Bardem last month - admits she sometimes takes the scissors to her own tresses because her hairdresser mother trained her how to do it when she was younger.
She said, "My mother is a hairdresser and owned a salon. It was so much fun. I learnt how to cut, colour and do blow-dries. If it hadn't gone well as an actress, I could have opened my own! Sometimes even now, I still take the scissors and cut my own or other victims' hair!"
Penelope also revealed how she hates staring at herself in the mirror for too long when she's having her hair and make-up done for big events.
She told Britain's InStyle magazine: "I only use full make-up when I'm making a movie or for a night out. Usually I have an hour-and-a-half to get ready for a red-carpet event. I always set up my BlackBerry and use the time in hair and make-up to study my script, otherwise you spend too long staring at yourself in the mirror."