Online social websites have achieved a phenomenal global growth over the last decade, attracting much attention from researchers worldwide. It is a known fact that young adults and teenagers are the most avid users of such sites. Based on the findings of several research studies in the Online Social Networks (OSNs) area, it has been found that these OSN sites are having a great impact on the lives of young people. But since most of the research works were carried out in other countries, it was found necessary and important to carry out a study in Mauritius on the impact of OSNs on the local youth. Such a study would provide an insight on the influence of OSNs on the behaviour and lifestyle of youngsters in the country. This paper reports the findings of a research work that was carried out in Mauritius targeting adolescents aging from 12 to 18 years where 4545 responses were collected through a survey. It was found that the majority of Mauritian youths were using OSNs on a large scale, mainly for communication purposes. According to this study, although OSNs have a positive impact on the adolescents, yet quite a large number of respondents reported having met with negative experiences on these online sites.