This work focuses on optimizing an efficient green synthesis of arylamidoximes from appropriate nitrile and hydroxylamine hydrochloride in water and triethylamine (1.6 mol equivalent) as a base at room temperature for 6 h. This new green synthetic methodology is compared with previously known methods. The main advantages of this new process reported are good yield, easier work-up and short reaction times. Moreover, some of the synthesized arylamidoximes converted to 1,2,4-oxadiazole derivatives 13a,b and 14 via the reaction with (4-acetylphenoxy)acetic acid 12.