The efficient production of PHA (bioplastics) using cyanobacteria is technologically challenging. Nevertheless, it remains as an attractive approach considering the fact that the carbon source comes directly from atmospheric CO2. In contrast, the more efficient production of PHA by bacteria relies on the use of valuable carbon sources such as sugars from starch and fatty acids from vegetable oils. Because of the growing pressure to reduce CO2 emission, the demands for plant products such as starch and vegetable oils are on the rise for use as starting materials for the production of biofuels and biobased materials. Therefore, the demands for plant products can be expected to increase, which inevitably will require more fertile land to be used for agricultural activities. In such a scenario, using cyanobacteria to produce PHA may become more promising because the large-scale cultivation of cyanobacteria does not require fertile land.