Objective: Given the effect of employee morale on organizational productivity and the low productivity of the public sector, it is critical to examine this variable and to discover its effective factors. Organizational goal ambiguity affects employee morale and this is blatantly noticeable in the public sector. This study is aimed at investigating the category of public service organizations in which morale is affected by goal ambiguity and determine the type of employees influenced by it. Methods: Data were collected using the standard questionnaires of PFS Employee Morale and Rainey's Organizational Goal Ambiguity. The study population consisted of 79 public service organizations of Yazd, from which 380 employees were selected through stratified sampling. Cross-loadings and the correlation between observable and latent variables were used to test the construct validity. SPSS and Smart PLS were utilized for data analysis Results: Organizational goal ambiguity decreased the morale in employees with a diploma degree, but increased it in female employees, employees with higher education, those with work experience less than 5 and more than 15 years, and those aged under 30 and over 40; however, it did not affect other groups. Moreover, this variable increased employee morale in bank and insurance job categories, but had no significant effect on other organizational groups. Conclusion: The results of this study emphasize that the use of organizational goal ambiguity increases the morale of the employees, provided they pay attention to individual characteristics and organizational mission.