Abstract We construct a sample of 70 clusters using data from XMM-Newton and Planck to investigate the Y _SZ,Planck – Y _SZ,XMM scaling relation and the cool-core influences on this relation. Y _SZ,XMM is calculated by accurately de-projected temperature and electron number density profiles derived from XMM-Newton. Y _SZ,Planck is the latest Planck data restricted to our precise X-ray cluster size θ ₅₀₀. To study the cool-core influences on the Y _SZ,Planck – Y _SZ,XMM scaling relation, we apply two criteria, namely the limits of central cooling time and classic mass deposition rate, to distinguish cool-core clusters (CCCs) from non-cool-core clusters (NCCCs). We also use Y _SZ,Planck from other papers, which are derived from different methods, to confirm our results. The intercept and slope of the Y _SZ,Planck – Y _SZ,XMM scaling relation are A = –0.86 ± 0.30 and B = 0.83 ± 0.06 respectively. The intrinsic scatter is σ _ins = 0.14 ± 0.03. The ratio of Y _SZ,Planck /Y _SZ,XMM is 1.03 ± 0.05, which is in excellent statistical agreement with unity. Discrepancies in the Y _SZ,Planck – Y _SZ,XMM scaling relation between CCCs and NCCCs are found in the observation. They are independent of the cool-core classification criteria and Y _SZ,Planck calculation methods, although the discrepancies are more significant under the classification criteria of classic mass deposition rate. The intrinsic scatter of CCCs (0.04) is quite small compared to that of NCCCs (0.27). The ratio of Y _SZ,Planck /Y _SZ,XMM for CCCs is 0.89 ± 0.05, suggesting that CCCs’ Y _SZ,XMM may overestimate the Sunyaev-Zel’dovich (SZ) signal. By contrast, the ratio of Y _SZ,Planck /Y _SZ,XMM for NCCCs is 1.14 ± 0.12, which indicates that NCCCs’ Y _SZ,XMM may underestimate the SZ signal.