We examined the importance of awareness for eyeblink conditioning by directly comparing singlecue delay eyeblink conditioning and single-cue trace eyeblink conditioning. During single-cue delay conditioning, participants who became aware of the stimulus contingencies early in the conditioning session conditioned no better than those who became aware later in the session or did not become aware. Thus, the level of awareness was unrelated to the overall level of conditioning across the session. In contrast, awareness of the stimulus contingencies early in the session predicted the success of single-cue trace conditioning. These data, together with earlier findings, show that awareness is irrelevant to single-cue delay eyeblink conditioning but is critical for single-cue trace eyeblink conditioning. The findings from the present study are related to previous findings for differential (CS+ and CS−) eyeblink conditioning and awareness.