Introduction:
The positive aspects of work of the underaged are perceived as including its economic value, positive role in the process of upbringing and socialization, and in the process of vocational training or economic education. However, on the other hand, attention is also paid to the negative consequences of work, such as threats to psychophysical and intellectual development, risk to health or even life, of the adolescents.

Material and methods:
The basis for this study was a survey conducted in a group of Polish adolescents aged 14–15 years. The study was conducted during 2016–2017 in a representative group of 5,468 schoolchildren from junior high schools, selected by the method of stratified sampling. The research material was collected using a questionnaire for the assessment of the phenomenon of economic activity among adolescents.

Results:
The results of the study showed that approximately 20% of Polish adolescents aged 14–15 performed paid work as hired labour, about 30% helped with running a family business (family farm, family business), and nearly 20% of respondents undertook independent economic activity. The majority of economically active adolescents are of the opinion that the work performed exerts a positive effect on their health. Evaluation of the work activities performed as dangerous, worse state of health of adolescents, and lower parameters of their physical development, exert the greatest effect on the perception of a given work as negatively affecting health. Negative evaluations of the effect of work on health also shape the perception of work as severe and experience of accident at work.

Conclusions:
These results may be used for the elaboration of practical recommendations in order to reduce negative effects, and enhance positive effects which work exerts on adolescents’ health.