Research has indicated that first language (L1) English speakers acquire derivational knowledge--the ability to understand and produce derived forms of a word--through increased exposure to the language (e.g., Anglin, 1993). Second language (L2) research has shown that L2 English learners tend to have limited productive derivational knowledge in comparison to L1 speakers (Schmitt & Zimmerman, 2002). However, the degree to which productive knowledge of derivatives differs between L1 speakers and L2 learners remains unclear. Moreover, there have yet to be any studies that have compared productive derivational knowledge of L2 learners at different educational levels (undergraduate and graduate students), nor has research examined L1 and L2 production of derivatives according to the frequency levels of the target items. The present study compared the ability of 21 L1 speakers, 18 English as a second language (ESL)-speaking graduate students, and 61 English as a foreign language (EFL) undergraduate students to produce the derivatives of 30 headwords. The results indicated that L1 speakers produced significantly more derivatives than ESL graduate students and EFL undergraduate students, and ESL graduate students outperformed EFL undergraduate students.