There is a great deal of uncertainty regarding his personal details; it cannot be ruled out that these refer to two different individuals.
In the directory of the Diocese of Oradea, he is listed as being from Oradea, but the year of his ordination is much later than the date of his ministry in the United States as recorded in other sources. He was a Slovak-Hungarian priest. Ferenc Dénes was known in the United States as Francis C. Denes. By the mid-1890s, he was already serving in New York as pastor of St. Elizabeth of Hungary Roman Catholic Church, where, amid tensions between Hungarian and Slovak parishioners, he strove to minister to the ethnically mixed community. In 1897, following the Lattimer Mine massacre, he traveled to Hazleton to assess the situation of the Hungarian strikers and explore ways to assist them. In 1905, he also played a role in organizing the Hungarian Catholic community in New York; the first meeting of the Hungarian Catholic Club was held in his apartment, which was located in the church building. From 1905 to 1907, he served in the Roman Catholic community of Heilwood, PA. Later, he worked in Akron and then in Barberton. Due to a serious illness (insomnia), he returned home and settled in Érkeserű. According to the directory of the Diocese of Oradea, he died in Oradea at a psychiatric hospital. He was buried from the Haller Chapel in the Olaszi Cemetery He was buried from the Haller Chapel in the Olaszi Cemetery
Mons. Dr. Endre Lestyán, Prelate-Canon and parish priest.

Further research is needed regarding his life.