An experimental study was conducted in order to compare the effects of the highly structured Distar Language 1 programme with the effects of the semistructured Shiach language programme on groups of socially disadvantaged children attending a state day nursery. Two randomly allocated groups of eight 3½–5 year old children were taught for eight weeks using one of the two programmes. For both groups, half were taught by a qualified teacher and half by a qualified nursery nurse, in groups of four children. Two further groups of six similarly aged, but less able, children were also taught Distar Language 1 for the same period by the teacher and nursery nurse. All children were tested before and after the language intervention programme on a variety of language measures. There were no major, statistically significant differences in improvement between the children taught by the teacher and nursery nurse nor between the two groups taught by the two different programmes. These findings are discussed in the context of the substantial claims made on behalf of, Distar. Practical problems of implementation, training and programme maintenance are discussed.