Electrochemical oxidation of sodium borohydride (NaBH4) in the presence of phenylacetylene derivatives (1a-f) in diglyme containing sodium iodide (NaI) as a supporting electrolyte using an undivided cell brought about the formation of the corresponding hydrocoupling dimers (2a-f) as the main products, which may be the first example in electrochemical transformation of acetylene derivatives. On the other hand, electrolysis of aliphatic acetylenes (3a,b) under the similar reaction conditions gave the corresponding primary alcohols (4a,b) as the single products. The difference and mechanism of both types of reactions were discussed.