The purpose of this research is to determine the influence of information systems and the work environment on the work effectiveness of employees at the Bontang City Population and Civil Registration Service. A total of 63 employees served as research sampling. The results were tested using multiple regression analysis, F test, t test and R2 test. In multiple linear regression testing, it was obtained that Y= 11.251+0.345X1 + 0.360X2. F calculation shows a value of 87.477 with a significance level of 0.000. Meanwhile, the Ftable value is 3.15. This shows that the F_count value is > F _table, namely 87.477 > 3.15 and the significance level is 0.000 < 0.05. Testing the  t_count value for the information system variable (X1) is greater than the t _table value (12.902 > 1.999) with a significance level below 0.05, namely 0.000. Meanwhile, the calculated t value for the work environment variable (X2) is greater than the t table value (4.302 > 1.999) with a significance level below 0.05, namely 0.000. The obtained value of R Square = 0.745 = 74.5%. This means that the independent variables information system and work environment together influence the dependent variable effectiveness by 74.5% and the remainder is influenced by other variables not included in this research. These results show that the information system and work environment together have a significant influence on the work effectiveness of employees at the Population and Civil Registration Service of Bontang City.