This study examined whether switching from amlodipine and atorvastatin treatment using two pills to an equal dose of single-pill therapy is useful in Japanese outpatients. We retrospectively reviewed data obtained from 94 outpatients for whom treatment with two pills, namely amlodipine and atorvastatin, was switched to an equal dose of single-pill therapy in 11 hospitals. The criterion for enrollment in this study was that patients had switched their medication without changing other anti-hypertensive or anti-cholesterol drugs. Neither systolic nor diastolic blood pressure changed significantly after switching to an equal dose of single-pill therapy, whereas low-density lipoprotein (LDL) cholesterol levels significantly decreased after the medication was switched from 94±24 mg/dl to 89±17 mg/dl (p=0.015). A switch from medication with two separate pills of amlodipine and atorvastatin to an equal dose of single-pill therapy resulted in an overall decrease in LDL cholesterol. The results indicated that the switch to single-pill therapy might be a useful treatment.