Castiglioni was recognized by Martindale-Hubbell for persistently maintaining its highest peer review rating of "AV" for the last 20 years. The AV rating is the highest possible peer review rating in legal ability and ethical standards issued by the nationally recognized Martindale-Hubbell Rating Service. He was also selected by the American Lawyer Media as a top rated lawyer in the labor and employment area by American Lawyer Media, a provider of news and information to the legal industry.
He was also recognized for the sixth consecutive year as a "Super Lawyer" in Connecticut and New England by Super Lawyers Magazine for his work in commercial litigation defense. He also was elected a James W. Cooper Fellow of the Connecticut Bar Foundation. The James W. Cooper Fellows nominate outstanding Connecticut lawyers, judges and teachers of the law to become James W. Cooper Fellows of the Connecticut Bar Foundation. The Fellows support activities and programs that further the rule of law and assist in the effort to improve the administration of justice in Connecticut.
Castiglioni also serves locally as a director of the Bank of New Canaan.