Writers with decoding and/or spelling difficulties often produce short, lower-quality texts and experience less fluent writing, frequently interrupted by long pauses at the word level. Research suggests that from adolescence onward, such writers become increasingly aware of their difficulties, which influences behaviours such as avoiding difficult-to-spell words and pausing for lexical decisions. The objective of this study was to deepen the understanding of how adolescent students with decoding and spelling difficulties engage in the task of text composition. In this multiple case study, we qualitatively investigated argumentative texts and writing processes produced by three Swedish upper-secondary students with such difficulties. Data were collected through keystroke logging and analyses of texts and keystroke logs provided detailed insights into their individual writing approaches. The results generally align with previous findings but reveal notable differences depending on the severity of the difficulties. Two students with moderate challenges paused extensively to consider spelling, formulation, and word choice, while one student with more pronounced difficulties wrote rapidly and briefly to complete the task quickly. This nuanced analysis highlights the diversity of writing profiles among students with decoding and spelling difficulties and underscores the need for tailored support to help them produce higher-quality texts.