Look Back in Anger has been recognized as a bombshell that blew up the old British theatre. However, when Look Back in Anger opened as the third play in the repertory of the English Stage Company at the Royal Court Theatre (a company that had been founded the year before precisely to stimulate new writing that would have contemporary relevance), it was not an immediate success. The critical reaction was mixed, but many of the critics, whether or not they liked the play, acknowledged its merits and those of its young author. Cecil Wilson in the Daily Mail assessed Jimmy Porter as a "young neurotic who lives like a pig," whose "bitterness produces a fine flow of savage talk, but is basically a bore because its reasons are never explained." But Wilson also said that the English Stage Company "have not discovered a masterpiece, but they have discovered a dramatist of outstanding promise, a man who can write with searing passion but happens in this case to have lavished it on the wrong play." John Barker, critic for the Daily Express, asserted that Look Back in Anger "is intense, angry, feverish, undisciplined. It is even crazy. But it is young, young, young." Milton Shulman of the Evening Standard attacked the play, saying. "It aims at being a despairing cry but achieves only the stature of a self-pitying snivel.'' Nevertheless, Shulman admitted that "Mr. Osborne has a dazzling aptitude for provoking and stimulating dialogue, and he draws characters with firm convincing strokes." Philip Hope-Wallace of the Manchester Guardian responded negatively to the play as well, calling it "a strongly felt but rather muddled first drama," but conceded that "they have got a potential playwright at last, all the same.'' Harold Hobson of the Sunday Times provided a positive assessment of the play and wrote of Osborne: "Though the blinkers still obscure his vision, he is a writer of outstanding promise." The critic for the New Statesman and Nation maintained that although Look Back in Anger was "not a perfect play," "it is a most exciting one, abounding with life and vitality.... If you are young, it will speak for you. If you are middle-aged, it will tell you what the young are feeling." But it was Kenneth Tynan of the Observer who created the most excitement with what is perhaps the most famous review in contemporary theatre. Tynan remarked: "That the play needs changes I do not deny: it is twenty minutes too long, and not even Mr. Haigh's bravura could blind me to the painful whimsy of the final reconciliation. I agree that Look Back in Anger is likely to remain a minority taste. What matters, however, is the size of the minority. I estimate it at roughly 6,733,000, which is the number of people in this country between the ages of twenty and thirty. And this figure will doubtless be swelled by refugees from other age-groups who are curious to know precisely what the contemporary young pup is thinking and feeling... It is the best young play of its decade."

In spite of the tremendous critical excitement it generated, Look Back in Anger was not financially successful during its first run. Part of the problem was thought to be the fact that rotating repertory—a practice new to 1950s London—was confusing to audiences who were unable to determine when any particular play was being performed. It was decided in August to cancel the other plays and run Look Back in Anger alone for eleven weeks, but even then the ticket sales failed to meet expenses. A twenty-five minute excerpt...