The influence of identity and similarity of repeated items on repetition blindness (RB) was investigated in two rapid-serial-visual processing (RSVP) tasks. In Experiment 1, the difference between correct recall for sentences containing repeated identical items and their controls was contrasted with the difference between correct recall for sentences containing pairs of orthographically similar items (fish – dish) and their controls. In Experiment 2 the same comparison was made between sentences containing repeated identical items and sentences containing pairs of orthographically identical items (the watch – to watch). The amount of RB elicited by the two conditions was measured at three different temporal lags. The results show that the function that describes performance over time for the repeated- identical (R-I) condition is different from that for the condition in which the items are orthographically similar (repeated-neighbor: R-N) or orthographically identical (repeated- homonym: R-H). The results are interpreted as suggesting that the decrements in performance observed for recall of the second occurrence of the repeated item in the R-I and the R-N and R-H conditions have different underlying causes.