The area which today covers the Doric House, the Roman East Bath and the Byzantine East Church at the Karian sanctuary of Zeus at Labraunda in south-western Turkey, was by Swedish archaeologists called the P-building and the R-bath during the early 1950s. The excavations of this area in 1951 and 1953 were documented in three excavation diaries by archaeologist Inge Dahlén, written in Swedish. These diaries have, however, never been published. This thesis therefore focused to analyse Dahlén’s three excavation diaries in terms of three aspects. The first aspect was to understand the archaeological work and documentation methods at Labraunda during the 1951 and 1953 excavations and consequently, determine how the archaeology functioned in practice at the site in the early 1950s. The second aspect was to present in what ways Dahlén’s diaries could contribute to the current and future excavations at the East Bath at Labraunda. The last aspect was to study Dahlén’s own archaeological interpretations which occured in the diaries. In order to present all the three aspects, the analysis and discussion on the diaries were organised into four headings: archaeological work, archaeological finds, stratigraphy and documentation methods. Studying the diaries based on these headings showed that certain improvements occurred in the diaries from 1951 to 1953. Dahlén’s excavation diaries reveal a large amount of archaeological data regarding the progress of the excavations and the numerous discoveries from the excavated areas. They need, therefore, to be taken into consideration for a better understanding of both the early and the new excavations that are being conducted at the same area.