We present the results of molecular dynamics simulations of liquid-supported monolayers of partially fluorinated amphiphiles. We have examined the structural consequences of molecular flexibility and different cross sections along the chain, introduced by partial block fluorination of linear alkane chain amphiphiles. It is found that monolayers of H(CH2)(7)(CF2)(7)COOH and F(CF2)(7)(CH2)(7)COOH amphiphiles have much greater disorder than does a monolayer of the corresponding perfluorinated or perhydrogenated amphiphile, with the disorder concentrated in the hydrocarbon portion of the chain. In contrast, a monolayer of F(CF2)(5)(CH2)(4)(CF2)(5)COOH has a well-ordered structure, which results from the suppression of the defects in the hydrocarbon block by the close packing of the fluorocarbon blocks. These results suggest the possibility of having a different class of monolayers with interesting properties that might be tunable by alteration of the structure of the amphiphile.