Let X = (X, d, μ) be a doubling metric measure space. For 0 < α < 1, 1 ≤ p, q < ∞, we define semi-normsWe will show that if a doubling metric measure space (X, d, μ) supports a (1, p)-Poincaré inequality, then the Besov space B α p,q (X) coincides with the real interpolation space (L p (X), KS 1,p (X))α,q, where KS 1,p (X) is the Sobolev space defined by Korevaar and Schoen [15]. This results in (sharp) imbedding theorems. We further show that our definition of a Besov space is equivalent with the definition given by Bourdon and Pajot [3], and establish a trace theorem.