Excess molar enthalpies, H-m(E), and excess molar volumes, V-m(E), Of 2-methoxy-2-methylpropane (MTBE) and four pairs of structural isomers of alkyl alkanoates (ethyl propanoate, propyl ethanoate, ethyl butanoate, butyl ethanoate, ethyl pentanoate, pentyl ethanoate, ethyl hexanoate, and hexyl ethanoate) have been determined at 298.15 K and at atmospheric pressure using a flow microcalorimeter and an Anton Paar density meter. H-m(E) and V-m(E) values decrease as the chain length of the alkanoates is increased, showing marked negative values for V-m(E). In contrast the H-m(E) values are small for all mixtures and vary from approximate to 95 J.mol(-1) (ethyl propanoate) up to approximate to-70 J.mol(-1) (ethyl hexanoate); they are positive only for mixtures with ethyl propanoate, propyl ethanoate, ethyl butanoate, and butyl ethanoate and negative for the other mixtures. Results have been correlated using the Redlich-Kister equation.