Marketing professionals are under a great deal of stress due to many antecedents of stress such as overload, role ambiguity, role conflict, responsibility, participation, etc. The stress badly affects the physical, cognitive and behavioural health and also effects professionalism as well as person's consistency in the environment and acceptance to change .The outcomes of stress is also seen on work performance. This study examines the relationship between job stress and work performance by using (n=3200) data of marketing professionals, designated as managers and assistant managers in multinational companies working in Pakistan. The data obtained through questionnaire and analysed on percentages. The comparison of the level of stress and performance showed that out of respondents who had low stress 58.33% were performing at a high level as compared to the 70% respondents who had high stress but their performance was low. The difference between the above two percentages was 11.67 % which supported the hypothesis. The results showed that job stress significantly reduce the performance of an individual. The results also suggested that organization should plan to help the employees in coming out of stress.