  We study the most general Multi-Higgs-Doublet Model (MHDM) with Natural
Flavor Conservation (NFC). The couplings of a charged scalar $H_i^{\pm}$ to up
quarks, down quarks and charged leptons depend on three new complex parameters,
$X_i$, $Y_i$ and $Z_i$, respectively. We prove relations among these
parameters. We carry out a comprehensive analysis of phenomenological
constraints on the couplings of the lightest charged scalar: $X$, $Y$ and $Z$.
We find that the general MHDM may differ significantly from its minimal
version, the Two-Higgs-Doublet Model (2HDM).
