Background It is difficult for conventional magnetic resonance imaging (MRI) to distinguish benign soft-tissue masses (STMs) from malignant masses. Purpose To quantitatively compare the diagnostic value of intravoxel incoherent motion (IVIM) and diffusion kurtosis imaging (DKI) in STMs. Material and Methods The data from 58 patients with STMs were retrospectively analyzed. The GE Discovery 3.0-T MRI scanner was used to acquire conventional MRI sequences, IVIM, and DKI images. The chi-square test, independent sample t-test, and Mann-Whitney U tests were used to compare the differences between conventional MRI features, IVIM, and DKI parameters (D-slow, D-fast, f, mean kurtosis [MK], and mean diffusivity [MD]) between the benign and malignant groups. Receiver-operating characteristic (ROC) curve analysis was also performed. Results Tumor size and depth are statistically different in STTs. Ds(low), MK, and MD values in the malignant groups are significantly lower than the benign groups (P < 0.05). However, D-fast and f values are not statistically different between the two groups. The area under the curve (AUC) of D-slow value (0.859) is higher than MD (0.765) and MK (0.676) values for identifying benign and malignant STMs. The D-slow value showed the best specificity (82.93%). The sensitivity and specificity of IVIM and DKI parameters are higher than that of conventional MRI sequences. Conclusion IVIM and DKI can be used to distinguish between benign and malignant STMs, with D-slow as the most meaningful parameter.