When the literature has been examined, there is not found any scale regarding teachers’ informal learning. That is why, the aim of this study is to develop a scale determining teachers’ informal learnings. Even though 600 teachers have been invited to participate in this study, 566 of them have voluntarily answered the scale. The study group of this research consists of 566 public school teachers who have worked at the Directorate of National Education in Amasya city, Turkey, 2015-2016 academic years. However. 33 of asnwered surveys have been discarded because of missing value and finally 533 of them analyzed by SPSS program. The researchers have put into practice the following steps: 1) creating of item, 2) consulting to authority, 3) pilot study, and 4) validity and reliability calculation process. As a result, the scale has 31 items even though it has 50 items at the beginning. After Exploratory Factor Analysis, the researchers have reached the scale with 7 factors. The first factor consists of 8 items, the second factor consists of 5 items, the third factor consists of 4 items, the fourth factor consists of 3 items, the fifth factor consists of 4 items, the sixth factor consists of 3 items, and the seventh and last factor consists of 4 items. İt is seen that load factor values change between 0.411 and 0.763. Moreover, variance of factors explain %62.913 of total variance. In addition, Cronbach’s Alpha value has been calculated to determine the internal consistency and found it as 0.89. Furthermore, the Cronbach’s Alpha value for each factor has been found from 0.83 to 0.91. Based on the above findings of this study, the researchers have come to the conclusion that the scale is valid and reliable to be able to employ for future studies. The researchers strongly suggest that other researchers might use this scale for their further studies