Introduction: Many authors share the view that maintaining body balance, as well as the formation of related behaviour patterns, is mainly dependent on the age of the subject and their gender. Therefore, the problem gains in significance with respect to pathological conditions resulting in analysed dysfunctions in the clinical picture. The paper aims to describe the formation of selected variables of body stability of a random group of people, standing upright with both feet on the ground and eyes open. The authors intended to find answers to the following questions: Are there any differences in the values of stability parameters depending on the age of the subject? Are there any differences in the values of stability parameters depending on the gender of the subject? Research material and method: The research involved a group of 120 people aged between 2 and 90, including 69 women (58%) and 51 men (42%). The average age was 37.58 years. They were divided into three age groups, with the first consisting of people between 2 and 19, the second made up of people between 21 and 43, and the third composed of seniors over 61 years old. The research was possible thanks to (COP) PEL 38 equipment, which allowed for the examination of the distribution of pressure on the ground, enabling an analysis of shifts in the centre of pressure in the foot. Result: The research allowed for the preparation of charts (stabilograms) depicting the areas of the body’s instability in the saggital and frontal plane, a chart of posture instability and parameters which can be helpful in further analyses, including: 1. Width, describing the extent of oscillations of a test subject, 2. Average deviation, 3. Average Speed of oscillations. The highest values of individual parameters were recorded in the case of the youngest age group. This goes to show that their posture is least stable, probably due to the fact that their balance system is not yet fully developed. The best parametric values were characteristic of the 21 – 43 age group. Conclusions: 1. The highest values of each parameter were attained by the youngest group. This fact points to the least stable posture in this group of all the examined, probably caused by their incompletely developed balance system. The best parameter values were attained by the group of people between 21 and 43 years old. 2. Gender has an impact on the balance of the erect posture, yet only in group 1, in which females are characterised by lower COG sway values than males.