In December 1998, a survey was carried out on the quality of trichiasis surgery, based on a random sample of 750 people chosen from the surgical records of 13 health centres of the provinces of Zagora and Errachidia (Kingdom of Morocco). Among those, 740 people were examined (participation ratio: 98.6%). The study population was mainly composed of women (63.8%) and people > 40 years (83.5%). The average age was 51.8 (48.5 for women and 57.4 for men). The most common surgical technique was the bilamellar tarsal rotation procedure. In 98.7% of cases, the operation concerned one of the upper eyelids, and in 58.5% of cases the right eye. At the time of the interviewers' visit, 11.1% of the people examined were blind (vision < 1/20 for the best eye) and 28.9% were visually impaired (vision > 1/20 but < 3/10). In addition, 17.6% of the eyes whose eyelids had been operated on rated as blind and 29% of them as visually impaired. The definition of recurrence was the presence of at least one or more eyelashes in contact with the eyeball. The recurrence rate is estimated to be 15.8%, divided into 2 categories: (1) Severe or total recurrence (2.4%) - At least one eyelash from the median part of the lid margin is in contact with the cornea - and, (2) Partial recurrence "One or more eyelashes affect the corners of the eyelids but never rub against the cornea" (13.4%). 14. 3% of the patients operated on were removing their eyelashes regularly which is a clear indicator of the failure of the operation. The following constitute risk factors for recurrence: being aged over 40, having been operated on in Errachidia province, having been operated on by a general practitioner or by an ophthalmologist. However, "time elapsed since the operation" does not appear to influence the recurrence rate in each of the three cohorts which were subsequently formed using the date of the operation (retrospectively). Most recurrences seem to develop during the first twelve months after the operation. The post-operational complications/sequelae detected were rarely sight-threatening, except in four cases, i.e., three ptoses and one case of tegumental necrosis with permanent exposure of the cornea. The most common complications were excessive rotation of the lid margin (over-correction) (2.3%) and cutaneous necroses with no exposure of the cornea (3.6%). In this series, 15.7% of the eyes examined presented central corneal opacity and 2.1% xerosis. In 1.6% of cases the eyeball was either destroyed (phthisis bulbi) or absent. A majority of patients (51.8%) was affected by persistent lacrimation or secretions.