Energy harvesting is an enabling technology for realizing an ambient power supply for wireless sensor nodes and mobile devices. By using flexible photovoltaic cells and piezoelectric films, we can readily harvest ambient energy if flexible energy harvesters can be realized. Conventional silicon circuits, however, are not best suited to realizing flexible large-area energy harvesters because they are not mechanically conformable to uneven surfaces such as shoes. To address this challenge, we propose an organic insole pedometer with a piezoelectric energy harvester in this paper as the first step toward ambient energy harvesting using organic flexible electronics.