The purposes of this research were to study job performance of professional nurses, Governmental Hospitals, Bangkok Metropolis and to examine the relationships between personal factors, (namely age, educational level and work experience), work achievement motivation, organization innovation quotient and job performance of professional nurses, Governmental Hospitals, Bangkok Metropolis. The subjects consisted of 380 professional nurses selected by multi-stage sampling technique. Data were collected using personal factors questionnaire, work achievement motivation, organization innovation quotient, and job performance questionaires. The instruments were tested for validity and reliability. The Cronbach's alpha coefficients were .86, .99, and .97, respectively. Statistical techniques utilized in data analysis were percentage, mean, standard deviation, contingency coefficient, and Pearson{7f2019}s product moment correlation. Major findings of this study were as follows: 1. The mean score of job performance andwork achievement motivation of professional nurses, Governmental Hospitals, Bangkok Metropolis were at the high level ([Mean] = 4.01, [Mean] = 3.55, respectively). However, the organization innovation quotient was at the moderate level ([Mean] = 3.37). 2. The relationships between personal factors,(age and work experience) and job performance of professional nurses were not statistically significant. 3. The relationship between educational level and job performance of professional nurses was statistically significant (C = .131, X[superscript 2] = 6.635, P< .05). 4. The relationship between work achievement motivation and job performance of professional nurses was positively significant (r = .42, P< .05). 5. The relationship between organization innovation quotient and job performance of professional nurses was positively significant (r = .57, P< .05).