The Billboard review in 1955 wrote that the material was mostly standards and that Tormé "renders them in a mellow, jazz-wize manner, and sales should be good among the hipsters".[2]AllMusic stated: "Tormé invested the songs with warmth and confidence. Recorded and released around the time he turned 30, It's a Blue World marked a turning point in Mel Tormé's recording career."[1]
In his 2023 book Let's Do It - The Birth of Pop Music: A History, Bob Stanley noted the similarities between Blue World and Frank Sinatra's In the Wee Small Hours, released earlier the same year. He went on to praise the record for its "twilight feel, dusk at the end of a warm summer's day".[3]