The present study aims to assess the relationship between Teaching Aptitude and Teaching Effectiveness of Secondary School Teachers, for this purpose of 100 (50 male and 50 female) teachers government and private high schools of Ballari district of North Karnataka. Teaching Aptitude Test Battery (TATB) by Shamim and Karim and Ashok Kumar Dixit (1986), and Teaching Effectiveness inventory by Umme Kulsum (2000) was administered on them to collect data. The‘t’ test mean, S.D and Carl Pearson’s Product moment correlation were applied for analysis of the data present study reveals that: (i) There is a positive and significant correlation between teaching aptitude and teaching effectiveness. (ii) There is no significant difference in the teaching aptitude of male and female teachers. (iii) There is no significant difference in the teaching effectiveness of male and female teachers. Keywords: Teaching Aptitude, Teaching Secondary School Teachers, Aptitude Test etc.