This article tries to expound the development of asymmetric regionalism and the principle of autonomy in the new constitucional systems in light of the different comparative law experiences (in Belgium, Canada, Germany, Italy, Spain, United Kingdom or United States). The author analyses the main characteristics and the most important organizational expressions of the principle of autonomy. Finally, he reveals how the positive outcome of the process of decentralization and of asymmetric autonomy are based on the ability of reaching a balance between the territorial communities' constitutional right to independence, on one hand, and the affirmation of the duty of solidarity and the principle of equality, on the other.