The contamination of the environment with microplastics has emerged as a global challenge. In addition, micro-bioplastics are an emerging source of contamination to compost. Although bioplastics are biobased and/or biodegradable, they require specific environmental conditions to completely decompose or degrade. Therefore, there is rising concern regarding environmental pollution from both microplastics and micro-bioplastics. Compost has been widely used for land-use application to maintain and improve soil fertility, but little is known about microplastics and micro-bioplastics in composts (Braun et al., 2021; Ruggero et al., 2019). Hence, to quantify and investigate the prevalence of microplastics in commercial composts, this study used Pyrolysis coupled to gas chromatography and mass spectrometry (Py GC-MS). Application of Py-GC-MS technique revealed that the compost samples contained plastic concentrations, such as polyethylene (PE), polypropylene (PP) and polyvinyl chloride (PVC), in detectable amounts, including bioplastics such as polylactic acid (PLA), polyhydroxyalkanoate, and polybutylene adipate terephthalate (PBAT). A few research studies have reported compost as a primary microplastics and micro-bioplastics source to the terrestrial environment (Cucina et al., 2021), influencing various structural and physicochemical changes in soil biome (Watteau et al., 2018; Vithanage et al., 2021). The presence of microplastics and micro-bioplastics within compost is an alarming environmental issue as there may be both environmental and human health related risks associated with it. Thus, this preliminary study, presenting the findings of quantitative research of microplastics and micro-bioplastics in compost will further provide the basis for conclusions about compost as a carrier of plastics in the terrestrial environment.