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Packing asymmetry between head-group and tail-chain of amphiphiles may induce buckling modulations in monolayers at air-water or oil-water interfaces. We consider three different cases associated with the head-tail asymmetry:(i) spontaneous curvature,(ii) molecular tilt divergence, and (iii) local composition variation in mixed monolayers. For a pure monolayer with non-zero spontaneous curvature, we find that, below some critical surface tension, an hexagonal array of" long-fingers" becomes more stable than the flat surface. This" long-finger" structure is not expected to remain stable against multilayer formation in the case of a Langmuir monolayer, but is relevant for monolayers at the oil-water interface. When the molecular tilt is non-zero, as often is the case in the liquid condensed phase of Langmuir monolayers, the coupling between curvature and tilt can also give rise to a first-order buckling transition …