Porous mixed-valent manganese oxides are a group of multifunctional materials that can be used as molecular sieves, catalysts, battery materials, and gas sensors. However, material properties and thus activity can vary significantly with different synthesis methods or process conditions, such as temperature and time. Here, we report on a new synthesis route for MnO2 and LaSr-doped molecular sieve single crystalline nanowires based on, a solution chemistry methodology combined with the use of nanoporous polymer templates supported on top of single crystalline substrates. Because of the confined nucleation in high aspect ratio nanopores and of the high temperatures attained, new structures with novel physical properties have been produced. During the calcination process, the nucleation and crystallization of epsilon-MnO2 nanoparticles with a new hexagonal structure is promoted. These nanoparticles generated up to 30 mu m long and flexible hexagonal nanowires at mild growth temperatures (T-g = 700 degrees C) as a consequence of the large crystallographic anisotropy of epsilon-MnO2. The nanocrystallites of MnO2 formed at low temperatures serve as seeds for the growth of La0.7Sr0.3MnO3 nanowires at growth temperatures above 800 degrees C, through the diffusion of La and Sr into the empty 1D-channels of epsilon-MnO2. Our particular growth method has allowed the synthesis of single crystalline molecular sieve (LaSr-2 X 4) monoclinic nanowires with composition La0.7Sr0.3MnO3 and with ordered arrangement of La3+ and Sr2+ cations inside the 1D-channels. These nanowires exhibit ferromagnetic ordering with strongly enhanced Curie temperature (T-c > 500 K) that probably results from the new crystallographic order and from the mixed valence of manganese.