Here he became acquainted with A. L. Crelle, who, encouraged by his ability and by that of Niels Henrik Abel, then also staying at Berlin, founded his famous Journal (1826).

He has been considered the greatest pure geometer since Apollonius of Perga.In his Systematische Entwickelung der Abhängigkeit geometrischer Gestalten von einander he laid the foundation of modern synthetic geometry.

In a second little volume, Die geometrischen Constructionen ausgeführt mittels der geraden Linie und eines festen Kreises (1833), republished in 1895 by Ottingen, he shows, what had been already suggested by J. V. Poncelet, how all problems of the second order can be solved by aid of the straight edge alone without the use of compasses, as soon as one circle is given on the drawing-paper.

Other geometric results by Steiner include development of a formula for the partitioning of space by planes (the maximal number of parts created by n planes), several theorems about the famous Steiner's chain of tangential circles, and a proof of the isoperimetric theorem (later a flaw was found in the proof, but was corrected by Weierstrass).

The most important are those relating to algebraic curves and surfaces, especially the short paper Allgemeine Eigenschaften algebraischer Curven.

His oldest papers and manuscripts (1823–1826) were published by his admirer Fritz Bützberger on the request of the Bernese Society for Natural Scientists.