This study assessed teachers' attitude towards validation of non-standardized achievement test in secondary schools in Borno State, Nigeria. Three objectives, three research questions and two null hypotheses were formulated. This was tested at 0.05 level of significance alpha. The U-test (Mann Whitney) was use to test hypothesis one while H-test was used to test hypothesis two. Survey research design was used for the study with the population of 8100 teachers within the four educational zones in Borno State. Proportionalsampling techniques was used to select 447 teachers. The analysis of the obtained data revealed that most teachers in Borno State have negative attitude towards validation of non-standardized achievement test. 267 teachers out of 432 had negative attitude only 165 teachers have positive attitude towards validation of non-standardized achievement test.There was significant difference in validation of non-standardized achievement testbetween teachers with difference qualification in secondary schools in Borno State (H=34.837, P =0.001). The study also revealed that significant difference do not exist in validation of non-standardized achievement test between experience and inexperience teachers in secondary schools in Borno State (U=1.065, P= 0.287). Base on these findings it was concluded that teachers in Borno State have negative attitude towards validation of non-standardized achievementtest, teacher qualification influence validation of non-standardized achievement test in secondary schools in Borno State while years of experience did not influence validation of non-standardized achievement test. It was recommended that Seminar and workshops should be organized on regular bases for teachers to upgrade and update their proficiency skill in test construction and validation and to motivate them.