The problem of the Dobrujan land frontier between the Bulgarian and Romanian national states, which officially came up after the San Stefano and Berlin (1878) peace treaties and was aggravated by the Peace of Bucharest (1913), dominated the bilateral relations for a few decades. The hereby study focuses on the period August 1914 – September 1915, when both South-Eastern European states were neutral towards the Great War. This context led to various proposals, projects and scenarios concerning the Romanian-Bulgarian relations and implicitly related to the fate of Dobruja. Our effort deals with three levels: the positions of the Great Powers, their relations with Bucharest and Sofia, and the direct relations between the two South-Eastern European states. Chronologically, this period is divided into several stages, marked by the Ottoman Empire’s entry in the war (1 November 1914), the deadlock of the negotiations between Bulgaria and the Entente (March 1915), Italy’s option to renounce neutrality (23 May 1915) and the onset of the final talks concerning Bulgaria’s option to join the Central Powers (July 1915). Among the most relevant sources, we need to mention the Romanian Military Archives from Piteşti and the works of synthesis written by the Bulgarian historians Georgi Markov, Ivan Ilčev and Žeko Popov, dealing with the period 1913-1919.