PURPOSE: To characterize the performance of students with signs of reading and writing difficulties, according to the school grade, error categories, reading fluency parameters, and the correlation between these variables. METHODS: Sixty children (48% girls), 3rd to the 5th grade students of public elementary schools, were evaluated. Thirty (ten from each grade) who presented signs of reading and writing difficulties composed the Research Group. Thirty children, paired by age and school grade, classified by their teachers as good readers, composed the Control Group. All subjects read aloud two lists of isolated items (38 words and 29 pseudowords) and a text. The reading sessions were recorded and transcribed, and parameters and errors were analyzed. RESULTS: Differences were found between the groups, and the Research Group had worse performances in all the studied variables. The following types of reading errors were more frequent in this group: non-compliance with the context-independent matching rule, omissions and additions, non-compliance with stress, complex errors, and refusals. Fluency rates and values were lower in the students with reading complaints, when compared to the good readers. Negative correlations were identified between reading fluency variables and the different types of errors, with different correlation values for each group, and showed that, in the present sample, the total number of errors decreased with school progression. CONCLUSION: The students with signs of reading and writing difficulties had worse reading fluency performance, and higher number of errors in all the grades studied. The correlations found evidenced the influence of the type of error on reading fluency, according to different patterns for each group.