Hi, I am able to override multiple config parameters using nose-testconfig plugin only if i pass the overriding parameters on commandline. e.g. nosetests -c nose.cfg -s --tc=jack.env1:asl --tc=server2.env2:abc But when I define the same thing inside nose.cfg, than only the value for last parameter is modified. e.g. tc = server2.env2:abc tc = jack.env1:asl I checked the plugin code. It looks fine to me. I am pasting the part of plugin code below: parser.add_option( "--tc", action="append", dest="overrides", default = [], help="Option:Value specific overrides.") configure: if options.overrides: self.overrides = [] overrides = tolist(options.overrides) for override in overrides: keys, val = override.split(":") if options.exact: config[keys] = val else: ns = ''.join(['["%s"]' % i for i in keys.split(".") ]) # BUG: Breaks if the config value you're overriding is not # defined in the configuration file already. TBD exec('config%s = "%s"' % (ns, val)) Let me know if any one has any clue.