Thyroid cancer (TC) is a frequently occurring malignant tumor with a rising steadily incidence. microRNA (miRNA/miR)-193a-3p is an miRNA that is associated with tumors, playing a crucial role in the genesis and progression of various cancers. However, the expression levels of miR-193a-3p and its molecular mechanisms in TC remain to be elucidated. The present study aimed to probe the expression of miR-193a-3p and its clinical significance in TC, including its underlying molecular mechanisms. Microarray and RNA sequencing data gathered from three major databases, specifically Gene Expression Omnibus (GEO), ArrayExpress and The Cancer Genome Atlas (TCGA) databases, and the relevant data from the literature were used to examine miR-193a-3p expression. Meta-analysis was also conducted to evaluate the association between clinicopathological parameters and miR-193a-3p in 510 TC and 59 normal samples from the TCGA database. miRWalk 3.0, and the TCGA and GEO databases were used to predict the candidate target genes of miR-193a-3p. Gene Ontology, Kyoto Encyclopedia of Genes and Genomes and protein-protein interaction network enrichment analyses were conducted by using the predicted candidate target genes to investigate the underlying carcinogenic mechanisms. A dual luciferase assay was performed to validate the targeting regulatory association between the most important hub gene cyclin D1 (CCND1) and miR-193a-3p. miR-193a-3p expression was considerably downregulated in TC compared with in the non-cancer controls (P