Molecular hydrophobicity (lipophilicity), usually quantified as log "P" where "P" is the partition coefficient, is an important molecular characteristic in medicinal chemistry and drug design. The log "P" coefficient is one of the principal parameters for the estimation of lipophilicity of chemical compounds and pharmacokinetic properties. The understanding of log "P" parameter in the undergraduate medicinal chemistry course seems to be a pitfall for students. This parameter has typically been measured using experimental methods, but recently, log "P" has been determined using computational methods. The number of publications about lipophilicity predictions has gradually increased over the last 10 years, but the number of programs available for an online prediction of this important parameter remains limited. An interesting tool for calculation of log "P" coefficients is presented: the Virtual Computational Chemistry Laboratory (VCCLAB) package. The package includes the ALOGPS 2.1 program suitable for log "P" calculations. This software is accessible online and may be easily mastered by the undergraduate medicinal chemistry student. (Contains 1 table and 1 figure.)