The nocturnal activity of burrow-nesting seabirds, such as storm-petrels and shearwaters, makes it difficult to study their incubation behavior. In particular, little is known about possible differences in the incubation behavior of adults at successful and unsuccessful nests. We combined the use of passive integrated transponder (PIT) technology and nest-temperature data loggers to monitor the incubation behavior of 10 pairs of Leach's Storm-Petrels (Oceanodroma leucorhoa). The mean incubation bout length was 3.31 +/- 0.59 (SD) days for individual adults at successful nests (N = 4) and 1.84 +/- 1.16 d for individuals at unsuccessful nests (N = 6). Mean bout length for pairs in successful burrows (3.51 +/- 0.56 d) did not differ significantly (P = 0.07) from that for pairs in unsuccessful burrows (1.80 +/- 1.20 d), perhaps due to one failed nest with a high mean bout length (4.15 d). The total number of incubation bouts per parent (4.3 +/- 1.9 bouts) did not differ with hatching success. Adults whose nests failed repeatedly exhibited truncated incubation bouts (< 12 h) prior to complete nest failure and were more likely than successful parents to make brief visits to nearby, occupied nesting burrows. Our results suggest that the decision by Leach's Storm-Petrels to abandon a nest is not an abrupt one. Rather, failed nesting attempts may be characterized by truncated incubation bouts where individuals pay the energetic cost of travel to and from the burrow, but do not remain long enough to successfully incubate the egg.