This study investigated whether repetitions of a wiki-mediated collaborative writing task with the intervention of consciousness-raising could enhance learners' attention to past-counterfactual conditional in English and their explicit and implicit knowledge development. Sixty learners worked in pairs to complete the same essay-writing task four times within a 5-week time frame. One group received deductive consciousness-raising after the initial task performance (TR + DCR); a second group engaged in inductive consciousness-raising (TR + ICR); and a third group only repeated the task (TR, control condition). Explicit and implicit knowledge gains were measured via an untimed grammaticality judgment test (UGJT) and an oral production test (OPT), respectively. On the UGJT, the TR + ICR led to significant immediate and delayed knowledge gains, while the TR + DCR only resulted in immediate enhancement. The TR + ICR resulted in gains in OPT and had some advantage over the TR + DCR and TR. These findings contribute towards our understanding of the effectiveness of consciousness-raising as a focus on form intervention activity between repeated collaborative task performances with respect to explicit and implicit knowledge at relatively higher levels of second language acquisition.