Although the Academy and the Royal Institute of Sciences, Letters and Fine Arts (1808-1851) lacked the necessary funds to furnish the Trippenhuis properly, there are nevertheless a number of items of historical value.

From the days of the Institute there are still the furniture from the old conference room and the coin cabinets received as part of the Hoeufft bequest in 1843. The 'Royal' chair - possibly late 18th-century - dates from the same period.

Furniture

After the Rijksmuseum moved out of the Trippenhuis, a major purchase of furniture was made in 1887 in order to furnish the now empty rooms and halls. The order, placed with the Pfersich family, consisted of large tables and forty chairs upholstered in leather. A number of these items, such as the conference table in the Board Room and twelve chairs with sculpted headrests, are still in the Trippenhuis today.

Other important items from the Academy period are the Knoll cupboard, acquired in 1881 to house the collection of the writer and poet Jacob van Lennep (1802-1868) donated by P. Knoll, and the fire screen by C.A. Lion Cachet, manufactured in 1925 for the Old Conference Room.

The chairs in the Old Conference Room are among the Academy's oldest possessions. These were procured in 1811 and consisted initially of a series of 60 chairs, which was later expanded. 

Paintings

When the Royal Institute moved in in 1812 there were eleven paintings in the Trippenhuis. Of these three are still hanging in the Trippenhuis. These are the large portrait of the Van Loon family painted by Dirck Metius in 1648; The Washing of Christ's feet, a copy after Rubens by an unknown artist; and the Mucius Scaevola, artist unknown. The other paintings, including the most valuable among them, the view of Juletha Bruk by Allard van Everdingen, were bequeathed in the past or given on permanent loan.
 
The Washing of Christ's feet and the Mucius Scaevola now serve as mantel paintings in the Rembrandtzaal and the Bilderdijkkamer respectively and, together with the four dessus-de-porte by Van Everdingen, are among the oldest possessions of the Academy. The remaining paintings in the Trippenhuis were obtained at a later stage. 

Portraits

The KNAW owns a small collection of portraits of scholars and artists that adorn the walls in various rooms of the Trippenhuis. Apart from the signed and painted portraits there are marble busts of Boerhaave, Chr. Huygens, Hugo de Groot, Van Kinsbergen, Rubens, Van Swinden, Hooft, Falck and Opzoomer. The sculptor P.J. Gabriël sculpted these likenesses on behalf of Admiral of the Fleet Jan Hendrik van Kinsbergen, a member of the Royal Institute and benefactor of the institution. The Van Kinsbergen bequest laid the foundation for a gallery of portraits of members of the Institute, comparable with collections of portraits in various university senate chambers.

Most of the painted portraits of members of the Institute and the Academy in the Trippenhuis came from bequests. Everwinus Wassenbergh donated his portrait, painted in 1808 by Van der Kooi, to the Institute. In 1831 the Academy received a portrait of Willem Bilderdijk painted by C.H. Hodges. In the late 19th century portraits were added of C.W. Opzoomer, painted in 1871 by J.G. Schwartze, and of J.H.C. Kern, painted in 1909 by J.P. Veth.