Assessment is an inherent part of good teaching for life long education. It is necessary to document the quality of one’s teaching for the sake of identifying those aspects of teaching that are good and those that need to be changed. In this paper, the author presents an insight into the principles involved, and methods adopted in the assessment of teachers. Instead of using traditional assessment techniques, the need of the hour, for life long education, is to make use of comprehensive individual performance-based measures. Teaching Portfolios help in the qualitative and / or quantitative performance assessment of teachers during their life-long journey of learning to tech. A teaching portfolio describes and documents multiple aspects pf one’s teaching ability. Presenting a vivid account on the uses of teaching portfolios both as a product and as a process, the author explains about what goes into a teaching portfolio. The concluding part of the paper deals with guidelines for developing a portfolio program. More