This study sets out to investigate the vocabulary learning strategies used by Sudanese learners of English, the vocabulary achievement of the same learners, and the relationship between strategy use and four learner factors: (i) the level of overall language achievement, (ii) the use of English as a medium of instruction for other school or university subjects, (iii) the number of years learning English, and (iv) the level of vocabulary learning achievement. The subjects were 300 Sudanese learners of English. The data was collected using self-report, observation, and interview, and was analysed using Cluster Analysis. The major findings suggest that the level of overall language achievement (" good" .and "poor") is related to word-learning strategy choice. However, the results also suggest that neither the "good" learners nor the "poor" ones form a homogeneous group. Different stages of development in strategy use were identified for the two groups. The choice of strategies can be said to be related to all the factors included in the analysis (i.e. the simple dichotomy of "good" and "poor" learners is by no means the only factor). The cluster diagnostics illuminated, inter alia which strategies the learners in a particular group (stage)use as a modus operandi and which ones typify the group. The results also given support to the "atomistic" variable sampling suggested in the study, in that the major differences between the groups lie in the micro- and not the macro-strategies the learners use in vocabulary learning.