The book contains the settlement names of the old Hungarian Bihar County in a dictionary format from the first data until 1600. The border-lines of the county changed relatively often over history, thus data of those village names which belonged to the county for a short period are also given. The author considers every toponym as a settlement name which is mentioned as such in any sources (works on historical geography, archives of charters and documents or other publications of historical sources) even if it is mentioned just once. The work aimed at completeness in gathering the toponymic data.

The dictionary entries are arranged according to the meaning and structure of the names. Some of them contain data that are morphologically identical, even if they do not refer to the same settlement (denotatum). Data that can be connected to different denotata can be found under separate numbers in the entries. Data referring to different settlements follow each other in the chronological order of the first occurrence.

Toponyms that are closely related from a structural and/or functional point of view are included in the same entry if they denote the same place and differ only in one morpheme, for example: Álcsi (< álcs: the old word form of Hungarian ács ‘carpenter’ + -i topoformant) ~ Álcs ‘carpenter’, Vásári (< vásár ‘fair, mart’ + -i topoformant) ~ Vásár ‘fair, mart’, Oláhtelek ‘Wallachian field’~ Oláhtelke ‘Wallachian’s field’. The form of the toponym that appeared the earliest is printed as a headword whereas the form that differs from the main one in just one morpheme occurs is given as a subheadword.

Toponyms applied to the same place but are totally different morphologically and structurally are printed in different dictionary entries, but references make their relations clear. The headword is followed by the localization of the denotatum of the name. Detailed information on the data is given in authentic transliteration faithful to the original spelling and this section is followed by the list of relevant sources. The data are arranged in a chronological order.

The historical-etymological analyses of the settlement names are printed in new paragraphs within the entries.

There are two indices attached to the dictionary. Apart from the authentic transliteration of forms with different spellings, the list of name elements that make up toponyms has also been completed. As an appendix to the dictionary, there is a sketch map showing the settlements of Bihar county.

A theoretical analysis of the onomastic material of the present work appeared as a separate monograph entitled A régi Bihar vármegye településneveinek nyelvészeti vizsgálata [The linguistic study of the settlement names of historical Bihar county] (Anita Rácz, Debrecen, 2005).