He was born in 19 June 1962 (age 53 years) Kannur, Kerala, to Reba Vidyarthi, a Kathak dancer of Bengali origin and Govind Vidyarthi, a Malayali theatre personality from Thalassery, Kannur. Ashish got his surname from his father, who took on the surname 'Vidyarthi' as a tribute to freedom fighter Ganesh Shankar Vidyarthi who died in Kanpur riots during the time of partition of India. He moved to Delhi in 1969 and joined the Bharatiya Vidya Bhavan's Mehta Vidyalaya, where he won acclaim for his performances as an actor in dramatic and comedic roles. He attended Hindu College and earned a BA in History. Vidyarthi film career began with a supporting role in Kannada Film Anand with Shivraj Kumar. He also starred with Suresh Gopi in Hijack (1991). His Break in Hindi Films came with Naajayaaz and Baazi. He became a very frequent villian. However he was associated with Brash and Crass Villians spewing dialouges rather than classy Pankaj Kapur type villians who were becoming the name of the game in Bollywood. As a result most of his films were not top of the line and were more of standard commercial masala fare. He did have some hits like Kaho Naa Pyaar Hai. He also acted in supporting or positive roles in some films such as Ek Rishta or a comical villian in Jodi No.1 and Haseena Maan Jayegi.
As films dried up in Mumbai, offers flooded him in South India. He soon played Villian in films C.I.D Moosa with Malayali Superstar Dileep, Baba as Ippo Ramasami with Rajnikanth,Ghilli and Azhagiya Tamil Magan with Joseph Vijay, Pokkiri and Athidhi in Telegu with Prince Mahesh Babu. He is among the # 1 Villian in South India along with fellow villian Mukhesh Rishi and Rahul Dev and has a very good career. He has acted with every major actor in all the South Indian Industries in over 40 films. He is currently acting in a serial 'Vaaris'as an autocratic father.