Assessment and evaluation are crucial to improving educational quality. Examining the opinions of teachers from various countries on in-class assessments can significantly enhance education systems. Similarities and differences in Uganda's and Turkey's educational systems justify comparing them. This study aimed to examine and compare the assessment methods used by teachers working in high schools in Uganda and Turkey to determine student achievement. The researcher administered the questionnaire to 119 Ugandan and 85 Turkish high school teachers working in public and private schools in both countries. The researcher used Casual comparative research. The Mann-Whitney U test was used for data analysis. The findings show that Turkish teachers use many in-class assessment methods more often than Ugandan teachers. Compared to Turkish teachers, Ugandan teachers view themselves as more capable of giving student feedback but less competent in taking measures to increase objective scoring. The article outlines further findings and provides recommendations.