Accumulation and aggregation of α-synuclein (α-Syn) are hallmarks of α-synucleinopathies such as dementia with Lewy bodies. Therefore, aggregation of α-Syn is considered a priority target for drug development, and aggregation inhibitors are expected to reduce α-Syn toxicity and serve as therapeutic agents. Here, we report that certain lysophospholipids (LPLs) species behave as inhibitors for α-Syn aggregation. The LPLs are small bioactive lipid molecules characterized by having a single carbon chain and a polar head group. The LPLs we used were extracted from Porcine Liver Decomposition Product (PLDP) which was previously reported to enhance cognitive function in healthy older adults. We found that the LPLs extracted from PLDP (PEL) reduced α-Syn aggregation in cellular model. Especially, four species of LPLs contained in PEL strongly inhibit α-Syn aggregation. Furthermore, we revealed that PEL increased normal cell viability in SK-N-SH cells. Finally we approached the mechanism of the LPLs’ inhibitory effect forα-Syn aggregation using in vitro assay and evaluated influences to various cellular functions known to be disordered in lesion. Taken all together, these studies indicate that the LPLs would be beneficial as a possible therapeutic target in the treatment of α-synucleinopathies.