This paper investigates the degradation of polyhydroxyalkanoates and its biofiber composites in both soil and lake environment. Time-dependent changes in the weight loss of films were monitored. The rate of degradation of poly(3-hydroxybutyrate) [P(3HB)], poly(3-hydroxybutyrate--4-hydroxybutyrate) [P(3HB--23 mol% 4HB)] and poly(3-hydroxybutyrate--3-hydroxyvalerate--4-hydroxybutyrate) [P(3HB--9 mol% 3HV--19 mol% 4HB)] were investigated. The rate of degradation in the lake is higher compared to that in the soil. The highest rate of degradation in lake environment (15.6 % / week(-1)) was observed with P(3HB--3HV--4HB) terpolymer. Additionally, the rate of degradation of poly(3-hydroxybutyrate--3-hydroxyvalerate) [P(3HB--38 mol% 3HV)] was compared to PHBV biofiber composites containing compatibilizers and empty fruit bunch (EFB). Here, composites with 30 % EFB displayed the highest rate of degradation both in the lake (25.6 % / week(-1)) and soil (15.6 % / week(-1)) environment.