Admission has been free of charge for decades, and attendance grew from 106,000 in 2007[5] to over 336,000 in 2017,[6] and 388,000 in 2019,[1] despite chronic staff shortages, and two of its four floors being closed since 2007.

[11][10] A selection from the geological collections was placed on display in the National Museum of Ireland site at Collins Barracks, this exhibition being opened on 27 September 2021 for 18 months.

[12] Among the many scientists who have studied the collections, Stephen Jay Gould did an essay based on the Irish elk in the museum.

Stuffed and mounted mammals, birds, fish — and insects and other animals native to or found in Ireland — comprise the rest of the ground floor.

[17] The museum was built in 1786 to house the Royal Dublin Society's growing collections, which had expanded continually since the late 18th century.

By 1850, with visitor numbers reaching 44,000, there were complaints of the cramped conditions during the restrictive public visiting hours of two days a week, nine months out of twelve.

As part of his strategy to encourage more donations, Carte published lists of the acquisitions and donors in the new Journal of the Royal Dublin Society.

[19] The building was designed by architect Frederick Clarendon in harmony with the National Gallery of Ireland on the other side of Leinster Lawn.

The foundation stone was laid on 15 March 1856 by Earl Carlisle, the Lord Lieutenant of Ireland, and the building was completed in 1857 by contractors Gilbert Cockburn & Son.

[17] It was connected to Leinster House by a curved closed Corinthian colonnade, which once held displays of the Geological Survey of Ireland.

The first exhibitions were mounted on the first floor and consisted of plants from the Botanic Gardens, Kiltorcan fossils, some birds donated by Carte, edible crustaceans and molluscs, Irish lepidoptera collected by Rev Greene, and fossils and birds collected by McClintock in the Arctic regions.

[17] While Dublin awaited the building of a National Gallery, the Natural History Museum hosted an exhibition of Decorative Art from Easter Monday 1858 which was opened by Earl of Eglinton.

Due to Carte's efforts in soliciting donations, the collections expanded considerably in the 1860s, but the Society only spent £373 on purchasing specimens.

On 18 November 1876 the RDS received a letter from the Secretary to the Treasury, William H. Smith, stating that there was an intention to obtain an Act of Parliament which would “vest all the buildings and land now held by the Royal Dublin Society in the Government” to allow “the State the requisite control over property and buildings upon which a large amount of public money is to be expended.” The Society was amenable to this, and relevant compensation was decided upon.

The 1890s saw the first female members of staff with Matilda Knowles and Jane Stephens appointed as technical assistants.

[17] A bronze statue of Surgeon-Major Thomas Heazle Parke was commissioned in the 1890s; it still stands at the front of the building.

During this time many of the staff members added to the collections; this included such as Valentine Ball, Richard J. Ussher, and Alfred Cort Haddon.

In 1927 the Minister for Education set up a Committee of Enquiry to report on purpose of the National Museum and how it could be improved.

The stairway was a very ornate structure, arising from Leinster House's former status as the home of the Royal Dublin Society.

[23] In the 2000s plans for an extension to one side of the existing building were considered, to provide more display space, and enable construction of lifts, costed at a total of 15 million euro.

[11] Other previous reports have also cited the under-staffing of the museum, along with the restraints of the 19th-century building, as hampering the development of the exhibitions and collections.

[24] The museum is included in the National Development Plan 2018-2027, as announced in 2018,[25] with allocation for the construction of a side extension, designed not to interfere with the integrity of the historic building, including display space, as well as an education space, a café, a shop, lifts and other disabled-access facilitation.

[1] The National Museum of Ireland has a unified organisation structure and budget, with a single overall Director, a Keeper for each major collection, including Natural History, and to some extent also location, and shared registration, education, IT and administrative functions.

[citation needed] Including the Keeper, there is a professional staff of just 3–5 in recent years, much smaller than in many comparable institutions, handling management, curation, classification, international cooperation and scientific advice.

In particular, the museum forms part of the global scientific community handling taxonomic queries and exchanging materials and reference data.

In 2020, the children's author and illustrator Peter Donnelly released the book The Dead Zoo, based on the building and its collections.

[30] One of a series of books written by school students, In Pieces, also uses the museum as a setting[31] as does the children's novel Molly Malone & Bram Stoker in Double Trouble at the Dead Zoo.