Consideration of every aspects of body motion that may contribute to balance recovery after unexpected slips is regarded to be fundamental for thorough understanding of slips and falls mechanism. The objective of current study was to assess the aging effect on the initial postural responses of the unperturbed foot after slip initiation. Totally 20 young and 23 old adults participated in a laboratory study, in which slippery surface was induced without their awareness. Unperturbed foot reaction time, contact velocity, and initial BoS (base of support) were quantified kinematically from motion analysis data after slip start. Apparent toe-touch strategy by unperturbed foot was found to be employed by most individuals. Initial contact dynamics was not found to be affected by either aging or slip outcome. The fact that all the individuals without using toe-touch strategy fell demonstrated the clear importance of unperturbed foot responses to avoid fall accidents.