We report here a newly synthesized cyanoimino-oxothiazolidine derivative, FPFS-410, which has properties to ameliorate both hyperglycemia and dyslipidemia. Treatment of genetically obese-diabetic db/db mice with FPFS-410 markedly ameliorates severe hyperglycemia and hypertriglyceridemia. Although the oxothiazolidine ring of FPFS-410 shares a structural similarity with other thiazolidinedione derivatives, reporter assays showed that FPFS-410 was much less potent to activate peroxisome proliferators-activated receptor gamma (PPAR gamma) as compared with pioglitazone. When 3T3-L1 preadipocytes were treated with FPFS-410, intracellular accumulation of lipids was facilitated in a similar fashion to pioglitazone. Moreover, treatment with FPFS-410 throughout the differentiation course resulted in a significant increase in glucose transport. These results suggest that FPFS-410 may provide a useful therapeutic candidate for diabetes mellitus and dyslipidemia.