Since the 1850s, the congress and conference industry has become an important economic factor for Wiesbaden.

From 1852 to 1914, around 300 congresses, conferences and meetings took place. In 1898, for example, the Congress for Internal Medicine(Internists' Congress) met in April, as it did every year, the German Medical Congress in July, and the Homeowners' and Landowners' Associations, the Central Association of German Merchants and the German Writers' Association in August and September. There was a certain focus on the medical field: in addition to the internists, associations of veterinarians and dentists, the German Red Cross, the Bakers' Association, the Alpine Association, the Federation of German Women's Associations and various smaller associations also held their meetings in the spa town in 1902.

Initiators were primarily the associations themselves; however, the meetings were often based on an invitation from the municipal authorities, the spa administration or local clubs. In 1875, for example, the city council invited the German Journalists' Convention to Wiesbaden for the following year.

The sometimes quite significant number of congress visitors and the ladies accompanying them was a first-rate economic factor for the hotel industry. At the Congress of German Natural Scientists and Physicians in September 1852, for example, 776 participants signed in on the lists on display, but their number was far higher than 1,000 due to the wives also attending.

The conference venues were the Kurhaus, the Wiesbaden Casino Society and the Paulinenschlösschen; the accompanying program often included a tour of the Kurhaus and Kochbrunnen, festive balls, garden parties with concerts, grand illuminations and concluding fireworks. The Walhalla, where the 30th German Blacksmiths' Day was held in June 1905 with 250 participants, and hotels such as the Victoria, which hosted the Freisinnige Volkspartei with 600 members including ladies in the same year, were also used for congresses.

The First World War and the subsequent occupation naturally brought a slump in congresses and conferences, but they were revived from around 1926 with meetings of the Association of German Electrical Engineers, dance school teachers and a few smaller events.

Many visitors also came to the supra-regional festive events of music and gymnastics clubs. In June 1861, the Liederkranz and Concordia choral societies brought around 400 singers to the town for a festival of the Rhine-Main Singers' Association, where folk songs were performed; the Duke made the riding arena available for this purpose. On the occasion of the 40th anniversary of the Wiesbadener Männergesangverein, over 1,500 singers from Germany and Austria came to Wiesbaden in August 1881. The 24th Middle Rhine District Gymnastics Festival in August 1899 was also well attended.

The development of congresses and conferences was slow after the Second World War until a tourism department was founded in November 1948, which was primarily responsible for organizing congresses. In 1949, 78 conferences with 10,211 visitors were counted again, and in 1954 the number rose to almost 100 and around 25,000 participants.

In the year following the construction of the Rhein-Main-Hallen, 223 congresses, conferences and trade fairs were recorded with 41,957 visitors. In addition to HAFA, other trade fairs were established; apart from the internists, real estate agents, the concrete and ceramics industries as well as German naturalists and doctors held their meetings in Wiesbaden. After a decline in congress and conference business since the 1970s, it is assumed that the construction of the new Rhein-Main-Hallen will result in a revival from 2018.