Quality has during the last decades become an important issue worldwide in education. Studies have been conducted from national to international levels. In sub-Saharan Africa countries, research on improving the quality of secondary education is at the forefront. Interest has been in finding solutions to the challenges caused by increased enrollment. But what are appropriate strategies for improving the quality of secondary school education in a country like Tanzania? What do teachers understand by the notion quality of secondary school education? This study deals with teachers' conceptions on these kinds of questions. Using an interview guide, the author has investigeted conceptions from teachers with a varied range of teaching experience, and subject areas. The results offer insights into a selected as secondary school teachers. The knowledge generated can therefore be considered releveant for viewing teachers' conceptions beyond the selected group of respondents, and can benefit different key actors in education as it provides a platform for strategies on improving quality in secondary school education.