  In this paper, we establish Iyengar type inequalities utilizing $\psi$-Caputo
fractional derivatives that is, fractional derivative of a function with
respect to another function, which is generalization of some known fractional
derivatives such as Riemann-Liouville, Hadamard, Erd\'{e}lyi-Kober. The
inequalities in this article are with respect to $L_{p}$ norms, $1\leq p \leq
\infty.$ The tools used in the analysis are based on Taylor's formulae for
$\psi$-Caputo fractional derivatives.
