This study presents a validation report of the Lecturer's Teaching Assessment Scale (LTAS) developed for the assessment of lecturer's teaching effectiveness in Obafemi Awolowo University, Ile-Ife, Nigeria. It also examined the factor structure of the LTAS, its construct validity, and internal consistency reliability coefficients. The study adopted the survey research design. A total of 13,000 students that completed the LTAS online constituted the sample for the study. The 34-item LTAS was used to collect data for the study. Collected data were subjected to reliability and factor analyses. Results showed that the LTAS has two subscales -Attitude to Teaching and Lecture Presentation and Organisation. The LTAS was adjudged to possess construct validity, and it was established through experts' judgement. The results also revealed that the LTAS was reliable (Cronbach Alpha reliability coefficient of 0.985, Spearman Brown's Split-half reliability coefficient of 0.998 and Gutman's Split-half coefficient of 0.997). Thus, the LTAS possessed adequate psychometric qualities that make it suitable for use among Nigerian undergraduate students.Keywords: scaling; teaching assessment; validation; reliability analysis; lecturer's assessment IntroductionOver the years, the assessment of academic members of staff during annual review of lecturers in Obafemi Awolowo University, Ile-Ife, Nigeria has been largely subjective as there was no formal, reliable and valid evidence to substantiate the rating of the quality of teaching of academic staff by their respective Heads of Department. The university recently became determined to ensure that lecturers are more committed to working hard than it was in the past, sustain its good rating via webometric ranking among its pairs in Nigeria and on the continent of Africa (Webometric ranking is a site that provides ranking of universities across the world. The site started publishing the ranking of universities in 2004 and the criteria for making the ranking are available on the website at http://www.webometrics.info/) and ensure excellence in learning and culture by trying to put into use an evidence-based approach for the assessment of every lecturer at the end of every semester, with a view to ensuring that lecturers strive to deliver their instructions with all the seriousness and innovations capable of enhancing learning positively.It was in the light of the foregoing that the Lecturers Teaching Assessment Scale (LTAS) was introduced to students for the assessment of the quality of teaching of academic members of staff in Obafemi Awolowo University, Ile-Ife, Nigeria. The LTAS is due for completion online (via the university's electronic portal) at the end of lecture periods of every semester by students who might have finished at least the first semester of 200 level (i.e. first semester of Part Two). This decision was exemplified by the fact that Lecturers themselves (having the premonition that their activities will be subjected to this type of assessment at the end of the sem...