I have already gfortran and g95 installed and working fine for all the system but numpy and scipy. By the way I'm using linux not MacOSX. My problem is that when I'm installing numpy gfortran (or g95) is detected but not at all the step and so f2py seem to be unable to use it. look at: line 92 in my attach file: find_executable('g77') Found executable /usr/bin/g77 gnu: no Fortran 90 compiler found gnu: no Fortran 90 compiler found but line 469: customize Gnu95FCompiler find_executable('gfortran') Found executable /usr/local/bin/gfortran I don't understand the problem. Thanks N.