The mobile telecommunications industry in Ireland is a mature industry and it has basically not been looked upon as to what attributes of service quality in mobile telecommunications affects a vital proportion, the young adult in their staying loyal to their brands. This research was carried out to establish the effects of customer satisfaction, perceived switching cost, brand trust, corporate image, perceived services quality and perceived network quality on the young adult's loyalty to the mobile telecommunications services in Ireland. A primary research was conducted with the use of quantitative technique to allow the cross tabulation of these variables and their effects on the young adults loyalty to their mobile telecoms service. The sample of 127 third level college students from, Dublin Institute of Technology, Trinity College Dublin, Dublin City University and Dublin Business School were administered online questionnaires to assess the effects of the attributes on their loyalty to the mobile telecommunications industry in Ireland. The result revealed customer satisfaction, perceived switching cost, corporate image, brand trust, perceived service quality and perceived network quality strongly affects customer loyalty in the mobile telecommunications industry in Ireland. Although this dissertation points out the exact items of the variable of customer loyalty that is positively and negatively affected by the attributes of service quality mentioned above, it also provides areas where marketers have to work on to keep a loyal subscriber base in terms of the service quality being provided.