Compared with single-label classification, multilabel classification is more general in practice, since it allows one instance to have more than one label simultaneously. Bayes' Theorem has been successfully applied to deal with singlelabel classification. In this paper, we proposed to tackle multilabel classification using Bayes' Theorem. We propose two approaches, coined as Pair-Dependency Multi-Label Bayesian Classifier (PDMLBC) and Complete-Dependency Multi-Label Bayesian Classifier (CDMLBC). PDMLBC takes advantage of label dependency between any two labels, while CDMLBC considers the dependency among a set of labels. In the experiments, we evaluate the performance of PDMLBC and CDMLBC on real medical data, the results show that both PDMLBC and CDMLBC methods outperform NB+BR on all metrics, and CDMLBC works best among the three methods.