The PISA project has steadily increased its influence on the educational discourse and educational policies in the now 70 participating countries. The educational debate has become global, and the race to improve PISA-rankings has become high priority in many countries. For governments the PISA-test is a high-stake test. Governments are blamed for low scores, and governments are quick to take the honour when results are improving. National curricula, values and priorities are pushed aside. The influence of PISA is of high importance also for science educators; the battle to improve test results may conflict with our work to make science relevant, interesting and motivating for the learners. This article tries to unpack some of the challenges and to raise some of the problems caused by PISA as a global measure of quality.