Lock Eben Etzebeth, loose forward Siya Kolisi and props Steven Kitshoff and Frans Malherbe all signed with the union until the end of 2015.
This will please WP and Stormers fans as the union has become renowned in recent years for letting talented young players slip through its grasp.
All four are still only 20 years old and were instrumental in the Stormers’ victory over the Sharks at Newlands on Saturday.
Kitshoff and Malherbe scrummed exceptionally well against the Sharks, which laid the platform for their eventual 15-12 victory.
Etzebeth and Kolisi were equally impressive, standing no inch back against more experienced opposition and showing good, controlled aggression.