In this article, we prove several congruences modulo 3, 4, 5, 8, 9, 12, 24, 27, 81, 243, and 729 enjoyed by the coefficients of certain mock theta functions. As an example, for the second order mock theta functionsμ2(q):=∑n=0∞(−1)nqn2(q;q2)n(−q2;q2)n2=∑n=0∞Pμ2(n)qn,B2(q):=∑n=0∞qn(n+1)(−q2;q2)n(q;q2)n+12=∑n=0∞qn(−q;q2)n(q;q2)n+1=∑n=0∞PB2(n)qn, we havePμ2(27n+26)≡25PB2(108n+103)(mod27) for all n≥0.