The memoir of Kemal Tanyolaç (1924-1995) mentions that he kept a record of all his sexual activities throughout his life, using a secret code in his unpublished diaries. Such record-keeping is not unheard of, appearing in diaries ranging from that of 18-century Jamaican slave owner Thomas Thistlewood to that of 20th-century Canadian writer Robertson Davies. Tanyolaç’s memoirs cover his childhood in Turkish Thrace in the 1920s, his high school and college years in Istanbul and elsewhere, and his working life as an accountant and economist for various state enterprises in Ankara from the early 1950s on. He says in his memoir that he thinks his records of sexual activity might be of interest or of use to the medical profession, suggesting he thought this information should be made public. The period during which his coded symbols appear in his diaries runs from January 1940 to December 1988. Thus it covers an important, culturally transformative period in Turkey’s history. This paper looks at what we can learn from this specific archive. The symbols give us much more than a simple tally of types and frequency of sexual activity. They show us more than the maturation of a single individual. In conjunction with other information in the diaries and the memoir, these symbols tell us about differing cultural and moral conditions in different parts of Turkey. They say a great deal about the availability of sexual partners in what is generally considered a sexually conservative society. They are also suggestive of changing social mores in Republican Turkey. There are periods of activity or lack of activity that can be associated with travels to or stays in specific locations, offering information about those locations. Given the nature of his code, Tanyolaç says little in the diaries about who he was engaging in sexual activities with, although in a few instances he either mentions a name or a location. More of that information can be put together from the memoir, and the two in conjunction are a very rich source. This is a resource that, although it is very specific to one individual and one type of activity, at the same time tells us much about the times and society of the man who kept these records.