After graduating from high school, Chester Laroy Nichols entered the University of Minnesota College of Law, and upon graduation was admitted to the Minnesota bar on June 10, 1910. Except for service in the army during World War One, he practiced law in Minneapolis. From 1919 to 1934 he was associated with John and William Nash, and from 1935 to his death on September 20, 1957, at age seventy, he was senior partner in Nichols, Mullin & Fernand.
Through his decades of practice, he was an active member of the Hennepin County Bar Association, and served as President in 1941-1942. In memorial services for the county bar association on May 10, 1958, Patrick L. Fernand recalled his partner:
"Chester L. Nichols was an industrious, loyal, scholarly and efficient lawyer and an estimable gentleman. Few lawyers have surpassed him in his devotion to the cause of his client. His forthright defense of what was right and just won for him the esteem and abiding friendship of all who came to know him. He was particularly admired by the members of the judiciary of Hennepin County and of the Supreme Court of Minnesota, who recognized in him an honest, able and straightforward advocate, a sincere friend and, above all, a man of sterling character.
"To those of us who were fortunate in being associated with him in the practice of law he has left in our memory an indelible mark of real friendship, of undying loyalty and of unimpeachable honesty. His many friends also knew him as an ideal family man; as a devoted and faithful husband, an exemplary father and a good neighbor."