The present study was motivated by the claim that attention and noticing are important for SLA and investigated the extent to which learners may notice the target form and its subsequent learning through noticing. To address the methodological concern about how to collect and analyze noticing data, the dictogloss procedure was employed following Swain’s (1998) suggestion. The transcripts of LREs of each pair of the learners were examined to capture the moments when their attention was drawn to form for their L2 output when performing a dictogloss. In general, the basic premise that the more attention to the form, the better its chance of learning was attested. There was also a positive relationship between the extent of noticing and subsequent learning and the learner’s readiness for the target form. This result led to the second research question which explores what factors constrain noticing and learning of the target form. Internal learner capacities (i.e. readiness, attentional capacity, bias, type of processing, and familiarity) appear to be the crucial constraining factors on noticing and subsequent learning. There was a disparity between the extent of noticing and learning outcomes in the case of some learners. This disparity seems partly due to the problem with the coding of noticing data. Therefore, the present study suggests that concerns still exist about how to best operationalize and measure the noticing of L2 forms. Finally, the limitations of this study are discussed and suggestions for future research are provided.