Summary. In this thesis there is treated legal institute solidary obligation relationship. It is one of that legal institutes which are not in the limelight of as many specialized works as they should be for their frequency of their use in practice. Although it could seem at first sight that the solidary obligation relationship is formed enough that there cannot arise any faintnesses there, but the opposite is true. There is not a one united theoretical view of solidary obligation relationship; the solidary obligation relationship can be understand as a one obligation relationship by the first view called theory of unity, but it can be understand as more obligation relationships which exist between creditor and every solidary debtors (in case of passive pluralism) or between debtor and every solidary creditor (in case of active pluralism) by the other view called theory of plurality. The most of specialized literature which take heed of solidary obligation relationship and which were written in recent time understand the solidary obligation relationship in accordance with the theory of plurality. This thesis in opposite to that specialized works understands solidary obligation relationship as a one obligation relationship in accordance with the theory of unity which is preffered in practice although it is...