Cardiac tissue engineering (CTE) is currently a prime focus of research due to an enormous clinical need. In this work, a novel functional material, Poly(3-hydroxyoctanoate), P(3HO), a medium chain length polyhydroxyalkanoate (PHA), produced using bacterial fermentation, was studied as a new potential material for CTE. Engineered constructs with improved mechanical properties, crucial for supporting the organ during new tissue regeneration, and enhanced surface topography, to allow efficient cell adhesion and proliferation, were fabricated. Our results showed that the mechanical properties of the final patches were close to that of cardiac muscle. Biocompatibility of the P(3HO) neat patches, assessed using Neonatal ventricular rat myocytes (NVRM), showed that the polymer was as good as collagen in terms of cell viability, proliferation and adhesion. Enhanced cell adhesion and proliferation properties were observed when porous and fibrous structures were incorporated to the patches. Also, no deleterious effect was observed on the adults cardiomyocytes' contraction when cardiomyocytes were seeded on the P(3HO) patches. Hence, P(3HO) based multifunctional cardiac patches are promising constructs for efficient CTE. This work will provide a positive impact on the development of P(3HO) and other PHAs as a novel new family of biodegradable functional materials with huge potential in a range of different biomedical applications, particularly CTE, leading to further interest and exploitation of these materials.