To determine the effect of piragliatin on the QTcS (QT-corrected study-specific) interval, a double-blind, double-dummy, placebo-controlled, active-comparator, 4-period, 4-treatment, 4-sequence randomized crossover trial was performed in 42 patients with type 2 diabetes mellitus who received 100 and 200mg piragliatin twice daily, placebo, and 400mg moxifloxacin (on day 1 and day 5 only) for 5days. In the categorical analyses, piragliatin did not have a clinically significant effect on the QTcS interval at either dose, and the majority of patients were categorized with low risk for maximum change from baseline (<= 30 milliseconds) and a maximum postbaseline QTcS interval as normal (<= 450 milliseconds). However, in the analysis of variance model, both piragliatin doses crossed the 10-millisecond threshold (100 mg twice daily on day 5, hour 1; 200 mg twice daily on days 1 and 5, hours 1 and 2) with P values indicating statistical significance. Headache and mild hypoglycemia were the most frequent adverse events associated with piragliatin treatment. There appeared that the effect of piragliatin treatment on the QTc interval was dose/exposure dependent following short-term multiple doses. Longer-term monitoring of electrocardiograms with pharmacokinetic exposure should continue, especially at conditions for potentially higher pharmacokinetic exposure.