On first publication, Steppenwolf was praised highly by German writer Thomas Mann and was a bestseller in Germany in 1927, but in spite of that, the novel met some fierce criticism. Some readers saw in the prominence of sex and sensuality of this novel a betrayal of the asceticism and spirituality of Hesse's previous novel, Siddhartha. Hesse received many indignant letters from readers complaining about the novel's unusual form as well as the perceived immorality of its treatment of sex and its apparent endorsement of drug-taking. Hesse was also accused of being unpatriotic.

In England, the novel received a rather wary reaction from the reviewer for The Guardian newspaper, who objected to the “macabre” quality of the work and suggested “that post-war Germany is becoming rather too morbidly preoccupied with the intellectual insanity, which, according to Herr Hermann Hesse, overtakes human life when 'two ages, two cultures...