After COVID-19 pandemic response, there has been a steady increase in the number of clinical trials with recombinant Adenovirus (rAdV) for human gene therapy, oncolytic cancer therapy or as a human vaccine. There are several common pitfalls developers might encounter in their journey. In drug discovery, there is several critical decisions significantly impacting the program’s overall success. Early consideration of safety and efficacy issues are fundamental, and it is crucial to build product lifecycle with rational CMC strategy to support the discovery process, to mitigate the risks during the early stage of development and to achieve straightforward approval process. Knowing about pitfalls on the road ahead and spending time and resources for critical decisions is the key to success in producing an adenoviral product and reach cost and time-efficient approval with a right first-time strategy.