The morphology and lateral growth rate of isotactic polybutene-1 (PB1) has been investigated for crystallization from the melt over a temperature range of 50-110 degrees C. The morphology of the PB1 tetragonal crystals was a rounded shape at crystallization temperatures below 85 degrees C, whereas at higher crystallization temperatures, lamellar single crystals possessing faceted morphology were observed. The kinetic roughening transition occurred at approximately 85 degrees C. Regime II growth mode on faceted growth fronts does not operate below 85 degrees C as the growth faces are rough. The morphology was therefore indicative of regime III growth on rough surfaces. However, the growth rate showed a single temperature dependence derived from the nucleation theory and thus does not represent a regime II-III transition. Possible mechanisms for the crystal growth of PB1 are discussed. (C) 2008 Elsevier B.V. All rights reserved.