Sensitivities to ipconazole of 50 isolates of the Fusarium (Gibberella) fujikuroi species complex (Ff complex) obtained from rice in Japan before 1994 (group A: before the launch of ipconazole) and 65 isolates after 1994 (group B) were investigated. Most isolates were identified as Fusarium fujikuroi, while 5 isolates in group A and 4 isolates in group B were identified as Fusarium proliferatum with species diagnostic PCR-RFLPs. The minimum inhibitory concentration (MIC) range, profiles in sensitivity to ipconazole and gibberellin production were similar in both groups. Gibberellin production was detected in the F. fujikuroi isolates with higher sensitivity to ipconazole but not in the isolates with lower sensitivity and F. proliferatum. High efficacy of ipconazole against rice “Bakanae” disease was confirmed by using the gibberellin-producing F. fujikuroi isolates in group B. No shift in sensitivity to ipconazole was verified and this may contribute to the stable efficacy against rice “Bakanae” disease.