Purpose <p>To explore the correlation between the histogram parameters from synthetic magnetic resonance imaging (syMRI) relaxation maps and histopathologic components in nasopharyngeal carcinoma (NPC).</p> Methods <p>Eighty NPC patients who performed syMRI examination were retrospectively enrolled between September 2020 to June 2022, and whole-tumor histogram parameters from syMRI relaxation maps (T1, T2, PD) were obtained. The relationship between histogram parameters and histopathologic components were investigated using the Spearman correlation coefficient, and stepwise multiple linear regression analysis was used to select the independent factors. Kaplan–Meier analysis and log-rank test were performed to compare differences in progression-free survival between low and high histopathologic components.</p> Results <p>The histogram parameters from T1 and T2 maps were significantly correlated with histopathologic components, including cellular, stromal, nuclear, cytoplasmic fractions, and nuclear/cytoplasmic (N/C) ratio (<i>P</i> &lt; 0.007), whereas no significant correlations were found between any histogram parameters from PD and histopathologic components (<i>P</i> &gt; 0.007). T1_mean was independently associated with cellular, stromal, nuclear fractions, and N/C ratio, and T2_skewness was independently associated with cytoplasmic fraction. High cellular, stromal, and nuclear fractions as well as N/C ratio, and low cytoplasmic fraction were correlated with poor progression-free survival.</p> Conclusions <p>The syMRI quantitative parameters were significantly correlated with histopathologic components in NPC, which aids in adjusting treatment strategies and predicting prognosis at an early stage.</p>