University science parks have long been recognized as a mechanism to aid innovation and regional development. However, research seeking to validate the benefits university science parks has produced inconsistent findings and has largely focused on developed contexts. A large body of literature has explored how internal factors such as the management, resources (human and financial), support mechanisms and business models may influence outcomes of university science parks. Less is known on how external factors may impact the performance of university science parks. We help fill this gap by exploring how regional external factors such as connections to triple helix actors, university type and government supported technology transfer offices may influence the patent performance of science parks in Turkey. The findings identify that the patent performance increases when the science park is associated with research-oriented universities, providing all other elements are held constant. Mature, government funded TTOs were also found to play a key role in increasing the number of patent applications. However, these effects change when considering the influence triple helix actors shareholders have. It was identified that the simultaneous existence of triple helix actor shareholders and research-oriented universities reduces the patenting performance of a science park compared to research orientated universities without triple helix actor shareholders. Therefore, our findings question the value of patents as indicators of performance within Turkish university science parks.