TWAS initiated its affiliateship category for young scientists in 2007. Each year thereafter, the five TWAS Regional Offices select up to five scientists under the age of 40 to be TWAS Young Affiliates for a period of five years. During their five-year tenure, TWAS Young Affiliates are invited to participate in five TWAS general meetings and conferences. The Academy's Regional Offices are located in Rio de Janeiro, Brazil; Beijing, China; Alexandria, Egypt; Bangalore, India; and Pretoria, South Africa (as of 2015; previously Nairobi, Kenya).
Generally, they nominate only one person per country among the five individuals selected each year to attend the TWAS General Meeting and Conference. To be eligible for selection, the young researchers must:
- be aged 40 or less on 1 January of the year in which they are selected;
- have been living and working in a developing country for at least the preceding three years;
- have an excellent track record of at least 10 international publications in peer-reviewed journals.
- will be invited to attend all TWAS General Meetings and General Conferences free of charge;
- are entitled to attend TWAS General Meetings as observers, i.e. they will be permitted to participate in the discussions, but will not have any voting rights;
- will be invited to attend regional meetings of TWAS Fellows organized by the Regional Offices;
- will be invited to participate in the activities of TWAS national chapters in their home countries (if such a chapter is active). They may be instrumental in starting one if it does not exist.
- will receive copies of TWAS publications such as the TWAS Newsletter, Year Book, and Annual Report;
- will have their biodata published in an annual Young Affiliate registry, to be made available at each TWAS General Meeting;
- are eligible for TWAS Prizes (unlike TWAS members);
- are encouraged to provide feedback to TWAS and the Regional Office on how the Academy can respond to the needs of young scientists in developing countries;
- are encouraged to provide information about TWAS programmes to their students and colleagues;
- are encouraged to seek out and nominate excellent scientists from developing countries, especially science- and technology-lagging countries, for TWAS awards;
- are encouraged to seek out excellent scientists from science- and technology-lagging countries and recommend their nomination for TWAS membership (via a TWAS member).