This study deals with the lawyer's civil liability for his professional mistakes towards the client. It is a comparative study that has been divided into two main sections and an introductory section which focuses on the definition of attorney and its historical development. The study describes in details the legal characterization of the relationship between lawyer and the client and the efficiency of the traditional rules (contractual liability and tortuous liability) when combining this relationship to them. This leads to the conclusion that such relationship falls under the general principle that has to be followed and its exception can be found when the lawyer miscarries his legal and professional duties. The study then goes into explaining and demonstrating the legal obligations sits sources cits importance and the degree to which the lawyer is bond to such commitments besides his commitment to his principles. Finally the study endsup by explaning the impact of the civil liabilty of a lawyer resulting from the breach of his commitment. It also demonstrates the concept of the compensation claim «its parties - its causes show to estimate the amount of compensation and the exemption from the claim.