Workaholic is a person that has an extreme obsession with his work. This paper wants to study workaholism among Iranian nurses (in Mazandaran province) and to answer the main question of the research. The research instrument is questionnaire. This study utilities questionnaire by applying the Spence and Robbins workaholic triad and distributing it among nurses. Data is obtained from one hundred and eleven male and female nurses in Mazandaran province hospitals. Samples include eighty four women and fifty two men. More than ninety five percent of respondents were less than fourty years old. Results show that male and female nurses in Mazandaran are workaholic and intensiveness of workaholism differs by the gender of nurses. As a result, job involvement in males is higher than females and work enjoyment in males is high too. But enthusiasm to work among women is higher than men. On the whole, workahism in males (X=3. 38) is higher than females (X=3. 33).