This study examined the validity of the SILL by performing a confirmatory factor analysis among 914 university students learning English in Korea. The results showed that all the fit indices including chi-square, RMSEA, CFI, and NFI used to test Oxford's two construct and six construct taxonomy of the SILL provided unacceptable fit to the data. These results might be in part due to the large number of the participants and in part due to the high correlations among the constructs. Implications of these findings were discussed, followed by future study areas to shed further light on the SILL and language learning strategies.