Purpose: This study aims to analyze the effectiveness of online teaching and learning in the higher education sector during the COVID-19 pandemic and thereby design and formulate strategies to overcome the lacunas, if any, to enhance teaching effectiveness. Design/methodology/approach: A survey was conducted to analyze how far students were able to adapt to online teaching and learning, access teaching platforms and afford it. It was also studied whether they were able to grasp and apply the concepts learned. A total of 600 questionnaires were given, and 372 complete responses were received. Structural equation modeling is employed to test the hypothesis. Confirmatory factor analysis (CFA) was conducted to test the model fit and measurement model. Findings: This study is first of its kind in India which aims to analyze the effectiveness of online teaching and learning environments. This research model is designed to identify the determinants of effective online learning and to overcome the lacunas existing in the prevailing online teaching methods. It can be applied not just during crises like the pandemic but also during normal times to make teaching and learning more economical, innovative and impactful. The present study examined the impact of five major determinants--adaptability, affordability, bandwidth, grasping and interaction--on online learning and its effectiveness during COVID-19. It was observed that all the determinants positively influence online learning effectiveness. Research limitations/implications: The scope of the study was restricted to three centrally funded Indian Universities. Other institutions were not part of the study. Originality/value: This study is the first of its kind done in the current COVID-19 scenario, and the outcome would help overcome the lacunas in the prevailing online teaching scenario across the globe and make it more effective.