The paper provides a cross-cultural analysis of selected linguistic realizations of persuasion in technical manuals as typical representatives of technical discourse. It aims to identify differences and similarities between the ways persuasive power is expressed in this type of specialized discourse in English and Czech L1 texts. The data comprises manuals to various technical devices and amounts to slightly more than 200,000 words. This specialized corpus (15 manuals in English and 15 in Czech) is assumed to enable the comparison of the ways in which technical communicators express persuasion. The investigation, which is conducted from the perspectives of corpus analysis and discourse analysis, focuses on the ways in which the interactive and dynamic process of persuasion is explicitly manifested: 1. directly (i.e. using directives expressed by imperatives of full verbs, modals of obligation, necessity, prohibition, and predicative adjectives expressing the writer’s judgement of the necessity to perform an action) and 2. indirectly (i.e. using other language means than directives, such as other modals than those related to obligation, necessity or prohibition, conditional clauses, rhetorical questions). The findings are expected to be relevant and applicable in the education domain to raise technical writers’ awareness of directives as useful persuasive strategies suitable for the production of effective well-written technical manuals since their quality including the appropriate degree of persuasiveness can influence prospective consumers to make a purchase of a particular technical device.