With the availability of frequency dictionaries, such as Alameda and Cuetos (1995) or the Corpus del Español (2002), it is now possible to explore the effects of frequency on linguistic items. The following is a study exploring the effects of frequency on Spanish affixed words. While the debate of dual-route versus single-route processing continues, the results of this study suggest that L2 Spanish speakers use a dual-route model and decompose morphologically complex words when the base frequency is higher than the surface frequency. L2 Spanish speakers perceive derived words with a higher base frequency as more complex than derived words with a lower base frequency. The results of this study do not suggest the same process occurs for native Spanish speakers. When asked to identify the more complex word of a pair, native Spanish speakers are just as likely to select the derived word with a lower base frequency as they are to select the derived word with a higher base frequency suggesting a single-route model.