Purpose <p>This research aimed to determine the relationship between work intensification and occupational fatigue in nurses using a cross-sectional and correlational design.</p> Methods <p>The sample included 597 nurses from public, private, and university hospitals in Istanbul, selected through convenience sampling. Data were collected using the "Nurse Information Form," the "Intensification of Job Demands Scale," and the "Occupational Fatigue Exhaustion/Recovery Scale." Analysis involved descriptive tests, correlation, and hierarchical linear regression.</p> Results <p>Results showed higher-than-average levels of both chronic and acute fatigue, with acute fatigue being more prevalent. The mean intershift recovery score was below average. A significant positive correlation was found between chronic and acute fatigue, while a significant negative correlation was observed between both fatigue types and intershift recovery. Work intensification levels were above average and correlated positively with chronic and acute fatigue, except for intensified career-related planning. Conversely, a negative correlation was found with recovery, except for intensified skill-related learning demands. Regression analysis revealed that demographic and occupational characteristics of nurses other than age, work intensification, acute fatigue, and intershift recovery explained 59.8% of chronic fatigue. For acute fatigue, these factors explained 11.2%, and for intershift recovery, 12.8%.</p> Conclusions <p>This study highlights the correlation between work intensification and occupational fatigue in nurses, suggesting that increased work intensity leads to higher occupational fatigue. The findings contribute to the literature and assist nurse managers and decision-makers in preventing occupational fatigue by re-evaluating and regulating current working conditions where job demands are intensified.</p>