This study assessed the variability within and among populations of three Egyptian onion cultivars (Red Behari, Giza-6 Mohasan and Line-70) during storage at normal room temperature.  Selection response was estimated towards improving storability of medium to large sized bulbs. The bulbs were checked at 45-d intervals to discard sprouted and disease infected bulbs.  The histograms analyses suggested normally distributed initial data for bulb weight, diameter, and length. The estimated descriptive statistical parameters revealed appreciable differences among and within the analyzed onion populations. Bulbs of cv Giza-6 Mohasan and Line-70 were excluded after 135-d in storage as all their bulbs developed sprouts. Red Behari cv showed sprouting after 225 d. At this time, the histogram for Red Behari cv strongly skewed left as a result of small bulbs predominance. Only some medium sized bulbs remained. These bulbs may be useful for population improvement in cv Red Behari or crossed with other cultivars.  The bivariate analysis for genetic and phenotypic associations showed high r values for bulb diameter and length with bulb weight during storage. These traits had a high genetic component as shown by heritability (H²) and coefficient of variation (cv). It is concluded that genetic variation exists for improving storability in Egyptian adapted onion. Red Behari medium sized bulbs may be further improved for shelf life by within population selection or after crossing with Giza-6 Mohasan. Indirect selection for bulb weight may be applied using bulb diameter.