Introduction Shift work associated with many health problems, work performance and injury. Disturbance of sleep quality is the main mechanism of shift work effects. Nurses are at risk of many occupational hazards and also shift work. The information about shiftwork and the association of sleep quality amongst nurses of Thailand is still limit.

Objective To study the association of shift work and quality of sleep and which pattern has highest risk of poor quality of sleep amongst nurses in university hospital in Northeastern region of Thailand.

Material and method One thousand and one hundred nurses were met inclusion and exclusion criteria with 75.5%(n=831) participation rate. The data was collected via questionnaire including personal information, shift schedule, depression screening questionnaire, obstructive sleep apnea screening questionnaire and sleep quality questionnaire (PSQI). Cross-sectional analytical study was conducted.

Result All patterns of shift work amongst sample were irregular shift work. There were statistically significant association between shift work and poor quality of sleep . Predominant backward shift pattern has higher association of poor quality of shiftwork than predominant forward shift pattern.

Conclusion Even shift work associate with poor quality of sleep but good strategy of shift work scheduling help to decrease risk of poor quality of sleep.